path: root/nxcomp/CHANGELOG

ChangeLog:

nxcomp-3.4.0-1

- Opened the 3.4.0 branch based on nxcomp-3.3.0-4.

- Changed version number.

- Updated copyright to year 2009.

nxcomp-3.3.0-4

- Check if the variable storing the ping time exceeded the maximum
  integer value.

- Recover incorrect sequence number when the proxy is not connected
  to an agent.

nxcomp-3.3.0-3

- Removed a condition in ClientChannel that caused a loss in event
  sequence numbers.

nxcomp-3.3.0-2

- Updated VERSION.

nxcomp-3.3.0-1

- Opened the 3.3.0 branch based on nxcomp-3.2.0-7.

nxcomp-3.2.0-7

- Solved a compilation problem on GCC 4.3.

nxcomp-3.2.0-6

- Changes considering that unsetenv() returns void on Mac OS X.

nxcomp-3.2.0-5

- Fixed TR03F02024. Assume the launchd unix socket as X socket.

- Changed the authorization cookie retrieval when using the launchd
  socket on MacOSX, in order to wait for the X server start.

nxcomp-3.2.0-4

- Fixed TR03F02026. Unset environment variable LD_LIBRARY_PATH before
  calling the exec function running nxclient.

nxcomp-3.2.0-3

- Fix addMsTimestamp() and subMsTimestamp(). Remove the check for
  a valid input in diffTimestamp() and diffUsTimestamp().

nxcomp-3.2.0-2

- Fixed TR12E01973. Now the correct number of bits are used for the
  number of points in a X_FillPoly request.

nxcomp-3.2.0-1

- Opened the 3.2.0 branch based on nxcomp-3.1.0-6.

nxcomp-3.1.0-6

- Always use a timeout of 50 ms to update the congestion counter.

nxcomp-3.1.0-5

- Solve the possible deadlock caused by both proxies running out of
  tokens at the same time.

- In ServerProxy::handleCheckDrop() copy the list since the function
  can delete the elements.

nxcomp-3.1.0-4

- Classes ProxyReadBuffer and ServerReadBuffer returned an invalid
  number of characters to read in the case of a readable() failure.

- Connections to proxy versions newer than 3.0.0 were not accepted.

- Reading options from file could fail if options contained spaces
  or other characters interrupting the fscanf()'s matching of input.

- The proxy link could not be flushed if a ping request was replied
  after the end of the read loop.

nxcomp-3.1.0-3

- Fixed a compilation warning on GCC 2.95.
  
nxcomp-3.1.0-2

- Solved TR09E01852. Modified the encoding of the number of rects
  in the XSetClipRectangles request.
  
nxcomp-3.1.0-1

- Opened the 3.1.0 branch based on nxcomp-3.0.0-46.

nxcomp-3.0.0-46

- Fixed TR09E01865 and TR08E01831. Assume the old behavior of compr-
  essing the CUPS, SMB, HTTP and Font channels when connected to an
  old proxy version.

nxcomp-3.0.0-45

- Retry the fork() 30 times, but only on Cygwin (Sob!).

nxcomp-3.0.0-44

- In the case of an error, try again to fork() after a second, for
  a maximum of 5 times. This seems to constitute a valid workaround
  to the intermittent fork() failures observed on Windows.
  
- Fixed NXTransDestroy() to show the 'broken connection' dialog in
  the case of a link failure on the client.

- Handled the 'terminating' and 'terminated' messages as new proxy
  stages.

- Force all the directories and files created by the library to be
  readable only by the user.

- Don't complain if the shared memory segment can't be initialized
  on Windows.

nxcomp-3.0.0-43

- Prevent the reallocation of the read buffer in the proxy and the
  agent transport if the buffer was borrowed by an upper layer.

- Let the house-keeping process remove the cache directories that
  are empty and have not be used since more than 30 days.

- Added the missing destruction of the ZLIB stream used for image
  decompression at proxy shutdown.

nxcomp-3.0.0-42

- In handleFastWriteReply(), moved the initialization of the 'next'
  pointer inside the '#ifndef __sun' block. This should fix the re-
  maining encoding problems on SPARCs.

nxcomp-3.0.0-41

- VMWare virtual machines can have the system timer deadly broken.
  In the case of timeout, try to send a ping regardless we are the
  client or the server proxy to force a write by the remote.

- Removed the messages 'Info: Using image cache parameters...' and
  'Info: Using image streaming parameters...' from the session log
  if the image cache is not enabled.

nxcomp-3.0.0-40

- Removed the messages 'Info: Shutting down the NX transport' and
  'Info: End of NX transport requested by...' at the session tear
  down.

- Removed the remaining log output.

nxcomp-3.0.0-39

- Don't reset the timer on proxy shutdown.

nxcomp-3.0.0-38

- Don't reinstall the signal handler if the signal was enabled and
  the NXTransSignal() action is NX_SIGNAL_FORWARD.

nxcomp-3.0.0-37

- Return a congestion level 9 if the agent channel is in congestion
  state.

- Set the idle timeout (used to update the congestion state) based
  on the link type. The timeout is 0 ms with link LAN and 50 ms in
  the case of MODEM, with the other values in the between.

nxcomp-3.0.0-36

- Changed the encoding of the RenderCompositeGlyphs requests. Use
  a separate cache for X and Y. Send a single bit for offset X and
  offset Y if they match the source coordinates.

- Always use the memcpy() in the handleFastWrite*() on Sun, as the
  alternative code doesn't work on SPARC if the buffer is not word
  aligned.

nxcomp-3.0.0-35

- Ensure a smooth transition between different congestion states.
  If the current congestion counter is greater than the previous,
  ramp up the value quickly by taking the current counter. If the
  new congestion counter is less than the previous, ramp down the
  reported value slowly by calculating the average of the last 8
  updates. Reset the congestion counter to 0 if no token reply is
  pending and the proxy is idle until a timeout.

nxcomp-3.0.0-34

- Calculate the current congestion as the average of the last 3
  frames sent.

nxcomp-3.0.0-33

- When sending a X_RenderCompositeGlyph update, send a single bit
  if the source X and Y match the values in cache.

- Save the check on the bytes readable from the proxy descriptor
  after the select.

nxcomp-3.0.0-32

- Send the X_GetImage replies uncompressed to better leverage the
  stream compression.

- Before entering in congestion state, force a read to see whether
  the remote proxy aborted the connection.

nxcomp-3.0.0-31

- Try to avoid using memcpy() in the channels' handleFastWrite*().

- Changed the copyright notices at the beginning of the files that
  were referring to NXPROXY to refer to NXCOMP.

nxcomp-3.0.0-30

- Set the agent and proxy descriptors as ready, when appropriate,
  also in the case of an interrupt.

nxcomp-3.0.0-29

- On the X server side, read more events from the X server just be-
  fore and just after having written some data. On the X client si-
  de, apply the same to the proxy link.

- X11 channels originate a congestion control code as soon as the-
  re is some data left from the previous write.

nxcomp-3.0.0-28

- Displaced automatically the "channel unresponsive" and "no data
  received from remote" dialogs if the error condition is ceased.

- Rewritten the channel drain procedure.

- Tried a different approach to the channel congestion handling.
  The X11 channels are not drained after a blocking write but only
  if a further write is requested and the channel is still in con-
  gestion state. Benchmarks show that this is still sub-optimal,
  compared to sending the congestion code immediately also for X11
  channels. See the next version.

nxcomp-3.0.0-27

- Ignored the agent option 'defer'.

- Dropped support for the 1.4.0 versions.

- More fixes to support the 1.5.0.

nxcomp-3.0.0-26

- The channel read buffer can inherit the data to be encoded from
  the caller, instead of taking it from the transport. This is le-
  veraged by the agent channel to save the copy.

- Ignored the agent option 'clients'.

- Removed the deprecated code checking the CPU limits.

- Removed the counters that were duplicated in the Statistics and
  the Control classes.

nxcomp-3.0.0-25

- Improved the effectiveness of the caching of the RenderComposite-
  Glyphs by using a differential encoding for the length, delta x
  and delta y of the first string.

- Better handle the compatibility between different formats of the
  cache files.

nxcomp-3.0.0-24

- Fixed the compatibility problem with the 1.5.0 versions.

- Removed the constants NXDisplayReadable, NXDisplayFlushable and
  NXDisplayCongestion. Now nxcompext has three distinct functions.

nxcomp-3.0.0-23

- Removed support for Rdp, Tight and Hextile packed images decod-
  ing since they have been made obsolete by the new NX server.

- Use the value 0 for the action is_hit and 1 for is_added. This
  increases the frequency of zeroes in the encode buffer, giving
  better compression.

- Changed the copyright attribution from Medialogic to NoMachine.

nxcomp-3.0.0-22

- Implemented an alternate encoding reducing the size of the int
  caches to 16 elements and transmitting the values in blocks of
  4 bits. Although this encoding reduces the effectiveness of
  the differential compression, it allows better compression of
  the final stream, resulting in a 10% to 20% gain in all condi-
  tions. The new encoding is experimental, as it would make the
  3.0.0 incompatible with all the previous NX versions. Use this
  package as a reference for future implementations.

nxcomp-3.0.0-21

- Encode the first two coordinates of a FillPoly message by using
  a differential encoding, thus the origin of the polygon is not
  included in the checksum. This is aimed to work in combination
  with the agent converting all the FillPoly requests to the rela-
  tive coordinate mode.

- Add the coordinate mode to the checksum of the PolyPoint and Po-
  lyLine messages so that it doesn't need to be encoded separately.

- Disable the streaming for all messages. This saves the encoding
  of a boolean for each message that could potentially be streamed.

- Don't try to match the block size when encoding a value based on
  an IntCache. This saves the additional bool in 90% of the cases.
 
- Removed support for the former RDP and RFB session types. 

- Due to the above changes, this version is incompatible with the
  previous 3.0.0 releases.

nxcomp-3.0.0-20

- Added support for the 'lossy', 'lossless' and 'adaptive' pack me-
  thod literals. These values activate the dynamic selection of the
  pack method by the agent.

- Made the 'adaptive' pack method the default for all link types.

- The default stream compression level is now 6 for link type ISDN,
  4 for ADSL and 1 for WAN. The default data compression level is
  always 1, except for LAN that is 0.

nxcomp-3.0.0-19

- Print in the session log the X11 display that the proxy is imper-
  sonating or where it is forwarding the connections.

nxcomp-3.0.0-18

- Implemented decoding of the PACK_BITMAP_16M_COLORS pack method.
  This is a very simple encoder removing the 4th byte in 32 bits-
  per-plane images. This encoder is intended to better leverage
  the stream compression on low bandwidth links.

- Removed the code cleaning the padding bytes in RenderAddGlyphs
  and RenderCompositeGlyphs as the operation is now performed in
  Xrender.

- Removed the "Info: Synchronizing local and remote caches." and
  "Info: Using remote server '...'." lines from the session log.

nxcomp-3.0.0-17

- Determine the CPU endianess at compile time only on Linux and
  Cygwin.

nxcomp-3.0.0-16

- Optimized the memory allocation of the ReadBuffer classes. The
  buffers from the Transport classes are used, when possible, to
  avoid the copy.

nxcomp-3.0.0-15

- Reworked the code dealing with the channel congestion control
  messages for increased efficiency.

- Removed the pending_ flag from the proxy and channel class mem-
  bers. If needed, the classes will query the transport buffers
  to see whether there is data pending.

- Removed the additional parameter from NXTransFlush().

- The proxy doesn't issue anymore a sync control message on a X
  reply. Anyway it will respond to the request for compatibility
  with older versions.

- Removed the dynamic selection of the encoding method for the
  X_QueryColors request and X_ListFonts, X_QueryColors, X_Query-
  Font replies. Now all of them use the differential encoding to
  better leverage the stream compression.

- Fixed to build on SUNs where we don't have endian.h.

nxcomp-3.0.0-14

- When handling partial proxy messages, don't try to determine how
  many bytes still need to be read if the ZLIB stream compression
  is enabled.

- If a message can't be located, the ReadBuffer class checks if it
  is possible to consume the data already in the transport buffer.

- Optimize the MD5 routines by determining the CPU endianess at
  compile time.

- Force Drawable and GContext to be CARD32 in NXproto.h.
  
nxcomp-3.0.0-13

- Changed the semantic of the NXDisplayFlushHandler callback. The
  function is called when new data is sent to the remote proxy or,
  with a 0 length, upon receiving a new token reply, so that the
  agent can update its congestion state.

- Added the NXTransCongestion() function. It returns a value bet-
  ween 0 and 9 indicating the congestion level based on the tokens
  remaining. A value of 9 means that the link is congested and no
  further data can be sent.

- Removed the congestion and synchronization callbacks. They are
  superseded by the new NXTransCongestion() implementation.

nxcomp-3.0.0-12

- Send the token replies at the end of the encode loop instead of
  flushing the buffer immediately.

- Fixed TR05E01687. Correctly detect CTRL-ALT-SHIFT-ESC keystrokes.

- Renamed the option 'block' as 'tile'.

- Ignored the option 'menu', targeting the X11 agent.

nxcomp-3.0.0-11

- Removed the 'interactive' attribute from generic channels. We now
  use the 'prioritized' attribute which yields the same result.

- Simplified the channels' read loop by always reading only once.

- The channels flush the link as soon as the token is exceeded even
  if the flush policy is set to deferred.

- Reserved more cache memory for the images when running a shadow
  session.

nxcomp-3.0.0-10

- Added the NXDisplayWriteHandler callback definition.

- Removed the code that forced the proxy to retain in the cache the
  images referenced at session startup.

- Disabled the persistent image cache since this is not supported
  by the current agent. This will save the overhead caused by the
  image house-keeping process.

nxcomp-3.0.0-9

- Fixed a cast problem in GetBytesReadable().

nxcomp-3.0.0-8

- Added the NXTransTime() utility. It return the time in milliseconds
  elapsed since the last call to the same function. Useful for bench-
  marking the Xlib layer.

- Ignored the option 'block' targeting the X11 agent.

nxcomp-3.0.0-7

- Ignored the options 'shadow', 'shadowmode' targeting the X11 agent.

- Added the session type 'shadow'.

nxcomp-3.0.0-6

- Fixed TR08D01484. Fixed a bug in the cleanup of the RenderAddGlyphs
  messages. We clean up only the glyphs with depth 8, width greater
  than 1 and pixmap byte pad 4.

- Added file COPYING.

nxcomp-3.0.0-5

- Updated the copyright notices to the current year.

nxcomp-3.0.0-4

- Imported changes up to nxcomp-2.1.0-6.

- Fixed TR12D01563. Changed the configure script to always build the
  library with the -fPIC option. This is related to the way SELinux
  works.

- Fixed the dependency from local endianess for 16-bit color RDP un-
  packing functions. This caused wrong colors to be displayed when the
  proxy and the X server were running on two separate machines having 
  different endianess.

- Fixed TR10D01523. The Channel::handleDrain() method now accounts
  for the fact that agent connections can't be drained.

- Changed the Tight and Hextile decoding functions to use the X ser-
  ver's byte order.

nxcomp-3.0.0-3

- Changed the main loop to handle the 3.0.0 version.

nxcomp-3.0.0-2

- Updated the file VERSION.

nxcomp-3.0.0-1

- Opened the 3.0.0 branch based on nxcomp-2.0.0-81.

nxcomp-2.0.0-81

- Fixed the dependency from local endianess for JPEG and PNG decomp-
  ression functions. This caused wrong colors to be displayed when
  the proxy and the X server were running on two separate machines
  having different endianess.

- Fixed the number of entries in the handleColormap() function.

nxcomp-2.0.0-80

- Fixed TR06D01404. Removed the warning issued when calling the
  AgentTransport::drain() method.

nxcomp-2.0.0-79

- Updated copyright to year 2006.

nxcomp-2.0.0-78

- Fixed a bug in the cleanup of the RenderAddGlyphs messages.

- Minor improvements to the encoding of the RenderCompositeGlyphs
  and RenderComposite requests.

- Added 'client' to the list of the ignored options.

nxcomp-2.0.0-77

- Added cleanup of the padding bytes in the RenderCompositeGlyphs
  and RenderAddGlyphs requests.

nxcomp-2.0.0-76

- Before adding the frame's bytes to the tokens, the frame length
  is normalized based on the stream compression ratio of the last
  frame sent. This avoids entering the drain loop too early when
  the data is highly compressible. 

- Moved the render messages' private data in a union to reduce the
  footprint of the render store.

nxcomp-2.0.0-75

- The action performed on the remote message store and the affected
  position are encoded as a single value. This saves approximately
  1 bit per each message.

- Created more Compat classes to handle the backward compatibility
  with the 1.4.0 and 1.5.0 versions.

nxcomp-2.0.0-74

- Added support for the RLE pack method and made it the default if
  the selected link type is LAN.

- Removed the legacy support for the 'render' option provided at X
  server side.

- When defining LAME in ClientChannel.h, the channel has the chance
  of suppressing more opcodes by the handleTaintLameRequest() call.
  This is for test purposes.

nxcomp-2.0.0-73

- The X_NXSetUnpackColormap and X_NXSetUnpackAlpha now carry their
  data in compressed form. The alpha data is compressed using the
  ZLIB RLE encoding, while the colormap data is compressed using
  the default ZLIB deflate.

- Thanks to the above changes, ZLIB data compression of all messa-
  ges which do not have a specific encoding is turned off, so that
  we can make better use of the final stream compression.

- Created new message structures to handle the compatibility with
  the old proxy versions. When connected to an old proxy version
  the agent should use the NXSetUnpackColormapCompat() and NXSet-
  UnpackAlpha() interfaces.

nxcomp-2.0.0-72

- Solved a compatibility problem with the 1.X.X versions due to the
  new render encodings.

nxcomp-2.0.0-71

- Improvements to X_RenderSetPictureClipRectangles.

- Fixed handleUnpack() to pass the correct byte order parameter to
  to the unpack alpha function.

- Added the --parent parameter to the client even in pulldown mode.

- Fixed a deallocation bug in StaticCompressor.

nxcomp-2.0.0-70

- Added compression of X_RenderSetPictureFilter, X_RenderSetPicture-
  Transform, X_RenderTrapezoids and X_RenderTriangles.

nxcomp-2.0.0-69

- Changed the format of the persistent cache to accomodate the new
  encoding of the render opcodes. Caches from the 1.4.0 and 1.5.0
  should be still loaded and saved correctly when connected to and
  old version of the library.

- Improved the encoding of the X_CreatePixmap, X_ChangeGC, X_Render-
  CompositeGlyphs, X_RenderComposite, X_RenderCreateGlyphSet, X_Rend-
  erFreePicture and X_RenderCreatePicture messages. Added new classes
  to handle the backward compatibility.

- Made the static compression and decompression code reside in the
  same class.

nxcomp-2.0.0-68

- Improved the encoding of the X_RenderCreateGlyphSet and X_Render-
  FreeGlyphSet requests.

nxcomp-2.0.0-67

- Modified the following session messages:

  From: "Session: Session starting at..."
  To:   "Session: Starting session at..."

  From: "Session: Session terminating at..."
  To:   "Session: Terminating session at..."

- Improved the encoding of the requests creating or freeing an XID.
  This affects X_CreateGC, X_CreateWindow, X_CreatePixmap, X_Render-
  CreatePicture, X_FreeGC, X_DestroyWindow, X_FreePixmap, X_Render-
  FreePicture.

- Added 'streaming' and 'backingstore' to the list of options used
  by agents.

- Modified the info messages to print the ZLIB compression paramet-
  ers to be more compact and only use two lines.

nxcomp-2.0.0-66

- When part of an agent, the proxy will wait for the NXTransDestroy()
  function to initiate the shutdown.

nxcomp-2.0.0-65

- Starting from this version the NX client can control the behaviour
  of the client proxy by monitoring the messages marked as "Session".

  At the early initialization the proxy will print:

  "Session: Session starting at '...'.

  The ellipsis here represent the current timestamp, as reported by
  the POSIX function ctime():

  Once the session is running, the proxy will print:

  "Session: Session started at '...'.

  At the time the session is being shut down, the proxy will print:

  "Session: Session terminating at '...'.

  Followed by:

  Session: Session terminated at '...'.

  The message "Info: Starting X protocol compression." is removed,
  replaced by the message 'Session started at...' with the same
  meaning. 

  Once the message 'Session: Session terminated at..." is read from
  the output, the client can optionally wait for the proxy process
  to complete and terminate with an exit code 0.

- The "Session" messages are not printed when the proxy is running
  on the NX server side, as part of an agent.

nxcomp-2.0.0-64

- Reduced the default token limit from 32 to 24. The synchronizat-
  ion callback is triggered by the tokens going below half the li-
  mit.

nxcomp-2.0.0-63

- Added -I/usr/include/c++ to makedepend.

nxcomp-2.0.0-62

- The house-keeping process is now started upon the initialization,
  if the memory cache is enabled, and, on the X server side, when
  the remote actually requested access to the image cache.

nxcomp-2.0.0-61

- Added a NX_HANDLER_SYNCHRONIZATION callback to NXTransHandler().
  The handler is called when the agent can use the available band-
  width to synchronize X objects that are corrupted or incomplete.

  The reason can be:

  NX_SYNCHRONIZATION_BEGIN:   The synchronizationis is allowed.

  NX_SYNCHRONIZATION_END:     The synchronizationis must stop.

  The reason can be determined by agents by using the NXBeginSynch-
  ronization and NXEndSynchronization values defined in NXvars.h.

- Bytes from 14 to 24 in the X_NXGetControlParameters reply report,
  respectively, the frame timeout, the ping timeout, the preferred
  image split mode and the split size threshold.

nxcomp-2.0.0-60

- The following messages used by the NX client and server have been
  changed. The NX client and server should be modified accordingly.

  From: "Info: Shutting down the link and exiting."
  To:   "Info: Shutting down the NX transport."

  From: "Info: End of session requested by remote proxy."
  To:   "Info: End of NX transport requested by remote"

  From: "Info: End of session requested by agent termination."
  To:   "Info: End of NX transport requested by agent."

  From: "Info: End of session requested by signal '...'."
  To:   "Info: End of NX transport requested by signal '...'."

  From: "Info: Shutting down the link and exiting."
  To:   "Info: Shutting down the NX transport."

  From: "Info: Waiting for cleanup timeout to complete."
  To:   "Info: Waiting the cleanup timeout to complete."

  From: "Info: Waiting for watchdog process to complete."
  To:   "Info: Waiting the watchdog process to complete."

nxcomp-2.0.0-59

- Added more debug information regarding the timing of packets sent
  and received.

- Added the possibility to redirect the log output to a file that can
  be later shared with nxssh running in "binder" mode. This is useful
  when testing the forwarding of the SSHD connection by nxssh to the
  agent. Activated by defining BINDER in Loop.cpp.

nxcomp-2.0.0-58

- Fixed the unpack alpha procedure to only rely on the image's byte
  order.

- Solved the X_PutImage encoding problem introduced in the 2.0.0-56
  version and restored the compatibility with the 1.5.0 version.

nxcomp-2.0.0-57

- Added a NXTransFile() function. It returns the name of the files
  used by the proxy for the current session.

  The type parameter can be:

  NX_FILE_SESSION:  Usually the file 'session' in the user's session
                    directory.

  NX_FILE_ERRORS:   The file used for the diagnostic output. Usually
                    the file 'errors' in the session directory.

  NX_FILE_OPTIONS:  The file containing the NX options, if any.
 
  NX_FILE_STATS:    The file used for the statistics output.

  The returned string is allocated in static memory. The caller must
  copy the string upon returning from the function, without freeing
  the pointer.

- Fixed the PANIC in the handling of the abort split messages.

- The encode and decode routines may write one byte past the nominal
  end of the encode buffer. This additional byte is now included in
  the payload. This is actually a bug, but harmless.

nxcomp-2.0.0-56

- Added the X_NXAbortSplit request. It can be used to interrupt the
  streaming of all the messages currently in the split store for
  the specified resource. Depending if the split store did or did
  not contain split messages, the client will receive an immediate
  end-split or no-split notification.

- Removed the split modes NXSplitModeEager and NXSplitModeLazy. The
  available modes are now NXSplitModeSync and NXSplitModeAsync. The
  mode NXSplitModeAsync replaces the two old modes and is now the
  default. Similarly to NXSplitModeEager, it makes the proxy split
  only messages that exceed a size threshold, but the threshold is
  generally smaller than in the previous versions.

  #define NXSplitModeDefault  0
  #define NXSplitModeAsync    1
  #define NXSplitModeSync     2

- Renamed X_NXSplit to X_NXSplitData, X_NXAbortSplit to X_NXSplitEv-
  ent.

- The proxy now enters a drain loop, when in congestion state, and
  waits until the decongestion. Also the X channels are drained if
  blocked.

- The select is restarted immediately if only the proxy is selected
  and the data read doesn't make a complete message.

- The size of the shared memory segment used by the X server proxy
  is now negotiated at startup and the selected value is printed in
  the session log.

- Added the option 'encrypted'. It tells the local proxy if it is
  running as part of a program providing encryption of the point to
  point communication. This is useful to determine if the proxy can
  block waiting for data or needs to yield to the client to let it
  handle the remote connection.

nxcomp-2.0.0-55

- Fixed handleRestart() to correctly send the end-split event only
  after the split sequence has been closed by the client.

- Fixed a possible memory error in the Keeper class occurring if the
  image caches were erased while in the middle of a loop.

nxcomp-2.0.0-54

- Added a '--parent' option when running the client in dialog mode.
  This is the process id that needs to be signaled in the case the
  user chooses to do so.

nxcomp-2.0.0-53

- Solved a bug in the abort split procedure. The procedure assumed
  that the split had to be at the head of the list. This may not be
  the case if the split was loaded from disk asynchronously, after
  a different split with the same checksum was recomposed.

- By defining STRICT in Loop.cpp, the number of available tokens is
  set to 1. This can be used to trigger the congestion more often
  than it would possible when testing the software with the default
  settings.

- Added more debug output to the procedures handling the streaming
  of the images.

- Reset the channel's split pending and congestion flags in the fin-
  ish procedure. Not doing so caused some additional loops at chan-
  nel shutdown.

- Fixed a bug on Cygwin that prevented the log files to be succes-
  sfully reopened when the size limit was exceeded.

- Failures to write to the agent transport are reported sooner when
  the channel is finished. This saves a few more loops at session
  shutdown.

nxcomp-2.0.0-52

- Started implementing a new handler to let the agent include arbit-
  rary data in the transport statistics. The parameter, in this case,
  is a pointer to a pointer to a null terminated string. The pointer
  is set at the time the handler is registered. The pointed string
  will have to be filled by the agent with its statistics data. For
  now, only the interfaces and the stubs exist.

- Disabled the timestamp cache as it still causes rounding problems
  when calculating the current bitrate.

nxcomp-2.0.0-51

- Removed SelectPackMethod(), not used anymore, from Pack.c.

nxcomp-2.0.0-50

- Added the X_NXFinishSplit request. It forces the proxy to comple-
  tely transfer all the split messages for the given resource, and
  then notify the agent.

- Fixed the statistics to not account the split bits to the control
  token.

nxcomp-2.0.0-49

- Fixed a bug that caused the split timeout to be reset even if a
  different channel had splits to send.

- Removed an error condition that arose when a split operation was
  requested by a different channel than the first to connect. The
  reason is that an auxiliary channel (like the one created by the
  server to store the keyboard configuration) can be the first to
  open a connection to the X server, then can come the agent, that
  is actually using the NX opcodes. The proxy will now simply print
  a debug message. 

- Removed a further error condition that was assumed by the proxy
  if a pending flush was detected while no channel was selected for
  output. This can actually happen if the channel was dropped and,
  in the meanwhile, the user requested the proxy statistics.

nxcomp-2.0.0-48

- Added a 'type' parameter to NXTransFlush(). The new NX_FLUSH_IDLE
  type should be used by agents when they have finished handling all
  their clients and are going to wait for more input. This is the
  case, for example, of the X agent returning from WaitForSomething()
  after having set a small timeout to find out if there are clients
  ready, or the case of a RDP agent finding that there are no opcodes
  to read from the RDP server. The 'idle' flush should be requested
  also when the X11 agent is waiting for a split to complete. When
  the flag is used, the proxy uses the available bandwidth to encode
  more low-priority data, like the payload of images being streamed.

nxcomp-2.0.0-47

- Added a new RGB image encoder. For now the encoder uses a static
  Z stream to compress the image data in the destination buffer and
  allows the agent to use the simplest encoding by still separating
  the alpha channel from the image data. The new encoder can be the
  the base for implementing color reduction by dithering or a color-
  mapped translation of the image similar to PNG, but without the
  PNG overhead and with the colormap being sent to the client using
  the NXSetUnpackColormap() opcode.

- Put the routines implementing static deflating and inflating of
  a ZLIB buffer from the Compressor and Decompressor classes to Z.h
  and Z.cpp, so that they can be reused by the new RGB encoder.

nxcomp-2.0.0-46

- Fixed a segfault arising when trying to start a child without the
  NX transport.

nxcomp-2.0.0-45

- Undefined the MATCH directive.

nxcomp-2.0.0-44

- Changed the encoding of the X_CreatePixmap, X_CreateGC, X_Render-
  CreatePicture, X_CreateWindow, RenderCreateGlyphSet.cpp. The Xid
  of the drawable is included in the checksum of the X_CreateGC and
  X_CreatePixmap message. This leverages the way GC and Pixmaps are
  allocated in the X agent to obtain better compression.

- Removed the code handling the reset of the proxy connection. This
  functionality was unused since when the persistence is handled by
  the agent.

- Added a specific section in the statistics output for the render
  extension.

nxcomp-2.0.0-43

- Fixed a bug that could have caused the sending of multiple 'end
  split' messages for the same split sequence.

- Added handling of the option 'strict'.

nxcomp-2.0.0-42

- Added a missing channel switch directive when encoding abort split
  messages at the server side. This could cause a decoding error on
  the client.

nxcomp-2.0.0-41

- Ensured that the link is flushed immediately on the X server side
  when important keyboard or mouse activity is detected in input.

- Implemented a timestamp cache to avoid calling gettimeofday() when
  it is enough to use the last timestamp gotten from the system. The
  cache can be disabled by undefining CACHE_TIMESTAMP in Timestamp.h.

nxcomp-2.0.0-40

- Added the karma delay field to the X_NXGetControlParameters reply.

- Solved a bug with the decoding of split messages likely to happen
  only when using link type LAN.

nxcomp-2.0.0-39

- Implemented separate flow control for the generic channels and the
  image streaming data.

- Improved the split procedure to load a message from the disk cache
  if found after it was originally discarded because locked.

nxcomp-2.0.0-38

- Renamed the 'shmem' option as 'shseg'. The 'shmem' option becomes
  specific to the agent and will be used together with 'shpix' option
  to indicate if, respectively, the shared memory extension and the
  use of the shared pixmaps must be enabled in the agent server. The
  new option will be instead used by the proxy to determine the size
  of the memory segment shared between the proxy and the X server.

- Added the 'shmem', 'shpix', 'keyboard' and 'clipboard' to the list
  of ignored options. The 'keyboard' option should become a synonym
  of 'kbtype'. The 'clipboard' option will tell the NX agent if the
  clipboard support should be disabled for security reasons.

nxcomp-2.0.0-37

- Ensured that, when running a raw session, the persistent cache is
  loaded and saved only once in the session lifetime.

- Added the 'product' keyword to the list of recognized options. The
  option is ignored by the proxy, but can be used by the client or
  server to facilitate the support.

nxcomp-2.0.0-36

- Added the remote version number in the X_NXGetControlParameters
  reply.

- Solved a bug related to the removal of the split stores.

- Removed the unused code dealing with the flush timeouts.

nxcomp-2.0.0-35

- Added an alert to notify the user about the failure of the XDMCP
  session.

nxcomp-2.0.0-34

- The active channels and the agent resources are now stored in a
  list container.

- Added the X_NXFreeSplit request. The request is currently unused
  because the split store is freed automatically when it becomes
  empty, but can be useful in future if we want to implement other
  otpimizations.

nxcomp-2.0.0-33

- There is now a split store for each agent resource. This allows
  the proxy to divide the bandwidth among the agent resources.

- A simple round-robin load-balancing is implemented, dividing the
  bandwidth equally among all the split stores.

- If there is a previous request being streamed for the same res-
  ource, cached messages are appended to the split store and then
  committed in the original order. This makes possible to stream
  the colormap and the alpha channel data even if the split invol-
  ves multiple PutImage or PutPackedImage operations in a single
  start-split/end-split sequence.

- Implemented the commit store class. Made the commit store expand
  the message in the final buffer, instead of leveraging the mes-
  sage store.

- Channels having a drop command pending are checked before trying
  to load or save the cache. This prevents a potential problem with
  the protocol violation error that could be reported by the client
  side proxy.

- The current bitrate is now calculated at the time the transport
  actually writes the data to the network, not at the time the data
  is appended to the transport by the upper layers. The reason is
  that the data can be compressed by the stream compressor and so
  we can calculate the real bitrate only after having flushed the
  ZLIB stream. This fixes the wrong numbers that could be reported
  by the statistics in the previous versions.

nxcomp-2.0.0-32

- More progress in the implementation of the new image streaming.
  This version has been tested to work when connecting to an 1.5.0
  server. Due to the significant changes in the way the streaming
  works in the newer versions, split is never activated by a 2.0.0
  server connecting to a 1.5.0 client.

- Fixed the NXTransClose() function to check if the fd matches the
  NX agent connection.

- Fixed the includes in Socket.h to compile on Solaris and MacOSX.

nxcomp-2.0.0-31

- Changed the NX transport functions that didn't require a NX fd
  parameter to include one. The value can be NX_FD_ANY to signify
  any running NX transport.

nxcomp-2.0.0-30

- More progress in the new implementation of image streaming.

- This version is apparently compatible with the 1.5.0 client but
  needs further testing.

nxcomp-2.0.0-29

- Implemented the NXTransHandler() interface and made the proxy
  use the callback, when it is installed, instead of the notifi-
  cation events.

- Modified the agent transport to report an EOF condition as soon
  as the channel is dropped, instead of reporting the error only
  after the proxy shutdown. This allows the agent to handle its
  clients while the proxy is handling the grace timeout.

- Added a test facility to verify if the client and server caches
  match at shutdown.

- More advances in the new implementation of streaming.

nxcomp-2.0.0-28

- Made the session shutdown faster, normally below 1 second. The
  grace time is now 500 ms once all channels have been dropped.

nxcomp-2.0.0-27

- The house-keeping process will now run a number of iterations
  (currently 100) and then will exit. The proxy will check the
  exit code and, if it was requested by the child, will restart
  it. This is intended to keep the memory consumption low, as I
  noted that after a big number of iterations the performance of
  the allocator start to degrade quickly.

nxcomp-2.0.0-26

- Started implementing the NXTransHandler() interface to let the X
  application hook a callback and be notified by the proxy when an
  event occurs. At the moment only congestion events are supported.
  The interface makes possible for the caller to provide a generic
  parameter. This parameter is passed back to the handler function.
  The parameter is expected to be the Xlib display pointer, given
  that the proxy doesn't have access to the Xlib structures.

- Moved all the internal variables shared between Xlib, nxcompext
  and the X server in nxcomp. Declarations and function prototypes
  moved to NXvars.h.

- Removed the NXGetCleanupParameters() and NXGetImageParameters()
  interfaces and the remaining references to the unused display
  buffer and image cleanup functions.

- In this version the images streaming functionality is disabled.
  Because of that, expect compatibility problems when connecting
  to a different nxcomp version.

nxcomp-2.0.0-25

- Forced the end of the session earlier if a shutdown has been re-
  quested by the local side but the remote proxy is not responding.

nxcomp-2.0.0-24

- Changed the loop deleting the file items in Keeper to pick the
  first element instead of looping through the iterator.

- More problems with the libstdc++ allocators. During the tests, I
  found that the Keeper class can leak industrial amounts of memory.
  Valgrind says that the objects that are not freed are the File
  items we allocate in collect(). As this looked suspicious, I log-
  ged the constructors and destructors and can say that everything
  is OK on our side. Unfortunately, by removing the spleeps used
  to let the program work silently in background, one can find that
  the memory occupation still grows by a MB every few seconds. This
  is less a problem on Windows, where the memory occupation remains
  almost constant. See the comment on __USE_MALLOC below.

- Increased the maximum size of a message that the proxy is allo-
  wed to cache to 4MB. This makes possible to cache many replies
  (like the X_QueryFont replies) that often exceeded the previous
  limit.

nxcomp-2.0.0-23

- Fixed a compatibility problem with the 1.5.0 that arose when
  encoding an image with caching and streaming temporarily disa-
  bled.

- Removed the __USE_MALLOC define in Types.h because this is what
  the g++ developers want. I'll try to avoid flames and will not
  comment on this.

- Added a --with-use-malloc configure option. This option should
  be used when building the release packages on GCC versions that
  support it.

- Started fixing the commit procedure to be able to deal with the
  alpha channel.

nxcomp-2.0.0-22

- Prevented channels from being dropped while in the middle of a
  read loop.

- Added a small utility ensuring that the SIGCHLD we receive in
  the main loop can be always identified as pertaining to an our
  child.

- Increased the space available for the control messages at the
  beginning of the encode buffer and ensured that there is always
  enough space for adding a token message, in the case this is
  required by the flush procedure.

- Made all cache files readable only by the user.

nxcomp-2.0.0-21

- Solved a bug in the streaming of images that caused the agent's
  clients to never resume when connected to an old proxy version.

nxcomp-2.0.0-20

- Disabled again streaming of the alpha channel data. By enabling
  it, the agent randomly fails to repaint the exposed regions. The
  reason is to be investigated.

nxcomp-2.0.0-19

- Implemented the split mode NXSplitModeSync. When this mode is
  selected, the proxy will not send data for the split at the head
  of the list until the  remote peer has confirmed that the message
  is not available in the image cache. This is going to be useful
  in combination with the lazy encoding.

- Improved the error detection in the case of failure when saving
  a recomposed split on disk.

- Added X_NXSetUnpackAlpha to the set of requests that is possible
  to stream.

nxcomp-2.0.0-18

- Enabled the 2.0.0 features that were disabled for test purposes.

- Changed the LICENSE file to state that the software is only made
  available under the version 2 of the GPL.

nxcomp-2.0.0-17

- Introduced a new channel of type 'slave'. Opening a slave channel
  should let the proxy fork a new NX client instance (or whatever
  is in the NX_SLAVE environment) and pass to it the channel's desc-
  riptors. This client instance should authenticate the peer, for
  example using the proxy cookie (see how this is implemented in
  nxsensor) and then negotiate the service to be used on the channel.
  This can be used to implement forwarding of arbitrary ports or ad-
  ditional services, like a simple file transfer protocol. For now
  the implementation is incomplete. Opening a slave channel will
  result in the remote proxy just dropping the channel connection.

- The proxy is forcibly flushed at the end of each loop. This is a
  temporary fix until the agents are updated to flush the proxy link
  on demand.

- Added a new alert to be used in the case the RDP session is closed
  and replaced with a new session using the same Windows account.

- Added a forward declaration of class RenderMinorExtensionStore in
  file RenderExtension.h to compile using gcc 4.0.X.

- Added removal of all .orig file when running a 'make clean'.

- The code uses again the 2.0.0 style shutdown (the one waiting for
  the watchdog process to terminate).

nxcomp-2.0.0-16

- Added the NXTransChannel() interface to allow agents to create
  new channels connected to the port that will be forwarded by the
  remote proxy. The function returns 1 on success, 0 if the NX
  transport is not running, or -1 in the case of error. On success,
  the descriptor provided by the caller can be used for all the
  subsequent I/O, including selecting the descriptor to check if
  I/O is possible. The type parameter not only tells to the proxy
  the remote port where the channel has to be connected, but gives
  a hint about the type of data that will be carried by the channel,
  so that the proxy can optimize the compression and schedule the
  traffic on the slow link.

  The type can be:

  NX_CHANNEL_X:     The channel will carry X traffic and it
                    will be connected to the remote X display.

  NX_CHANNEL_CUPS:  The channel will carry CUPS/IPP protocol.

  NX_CHANNEL_SMB:   The channel will carry SMB/CIFS protocol.

  NX_CHANNEL_MEDIA: The channel will transport audio or other
                    multimedia data.

  NX_CHANNEL_HTTP:  The channel will carry HTTP protocol.

  NX_CHANNEL_FONT:  The channel will forward a X font server
                    connection.

  Only the proxy running at the NX server/X client side will be
  able to create a X, CUPS, SMB, MEDIA and HTTP channel. A proxy
  running at the NX client/X server side can create font server
  connections. The channel creation will also fail if the remote
  end was not set up to forward the connection.

  To create a new channel the agent will have to set up a socket-
  pair and pass to the proxy one of the socket descriptors.

  Example:

  #include <sys/types.h>
  #include <sys/socket.h>

  int fds[2];

  if (socketpair(PF_LOCAL, SOCK_STREAM, 0, fds) < 0)
  {
    ...
  }
  else
  {
    //
    // Use fds[0] locally and let the
    // proxy use fds[1].
    //

    if (NXTransChannel(fds[1], NX_CHANNEL_X) <= 0)
    {
      ...
    }

    //
    // The agent can now use fds[0] in
    // read(), write() and select()
    // system calls.
    //

    ...
  }

  Note that all the I/O on the descriptor should be non-blocking,
  to give a chance to the NX transport to run in the background
  and handle the data that will be fed to the agent's side of the
  socketpair. This will happen automatically, as long as the agent
  uses the XSelect() version of the select() function (as it is
  normal whenever performing Xlib I/O). In all the other cases,
  like presumably in the agent's main loop, the agent will have
  to loop through NXTransPrepare(), NXTransSelect() and NXTrans-
  Execute() functions explicitly, adding to the sets the descript-
  ors that are awaited by the agent. Please check the implementa-
  tion of _XSelect() in nx-X11/lib/X11/XlibInt.c for an example.

nxcomp-2.0.0-15

- Some changes aimed at finding a workaround to the unreliability
  of the font server connections. The X server seems to be really
  picky about the network latency, so we try to read immediately
  from the channel just being created, instead of waiting for a
  new loop. Additionally the proxy will keep reading from the font
  server connections even after the maximum length of the frame
  is exceeded, in the hope that it will be able to send a complete
  message in a single frame.

- updated the various internal consistency tests run when the TEST
  or INFO flags are enabled.

nxcomp-2.0.0-14

- It seems that the closure of the socket sometimes takes several
  seconds, on Windows, after the connection is broken, with the
  result that the alert can be shown long after the user has gone
  after the failed session. We now skip the closure of the proxy
  link on Windows if we are about to exit.

- The code uses the 1.5.0 style shutdown (the one waiting for the
  term signal in the main process) to be able to test the library
  with the old server. To activate the new shutdown procedure be
  sure the define SHUTDOWN_COMPATIBLE_1_5_0 is unset.

nxcomp-2.0.0-13

- Ensured that static members in channels are reset at the time a
  new proxy is created.

- Adjusted the token parameters for link modes other than modem.

nxcomp-2.0.0-12

- Handled compatibility with 1.X.X versions not sending the count
  field in the token.

- The proxy link is now flushed automatically if the agent has not
  set the deferred flush mode.

nxcomp-2.0.0-11

- Significant modifications to allow the proxy to keep data in the
  encode buffer across multiple loops, until the data is flushed
  because an explicit request by the agent or. Besides maximizing
  the amount of data sent in a single frame, this makes it possi-
  ble to move any packet coalescence strategy in the agent, while
  still using an 'immediate' flush policy.

- Modified the procedure handling the proxy congestion. Each token
  now carries a counter which represents the multiple of TokenBytes
  data bytes that need to be confirmed by the remote end. The ser-
  ver side proxy will need to reply by including the value of the
  counter. When sending a new token, the tokens are decremented by
  the counter and the client side proxy enters in congestion when
  the available tokens becomes zero or negative.

nxcomp-2.0.0-10

- Implemented specific encoding of the X_NXSetCacheParameters
  request.

- Handled the compatibility with older versions not supporting the
  new request. In this case the request is handled at the local si-
  de, preventing the X requests to be cached or split, even without
  the cooperation of the remote side.

nxcomp-2.0.0-9

- Modified the shutdown procedure to not rely on the TERM signal
  when the proxy needs to wait for the server to complete. We will
  now print the following message in the session log:

  Info: Watchdog running with pid 'n'.
  Info: Waiting for watchdog process to complete.

  The NX server will have to kill the process with the given pid
  to mandate the proxy shutdown. This solves the TR11C01192.

- Added the X_NXSetCacheParameters request. It tells to the proxy
  how to handle caching of X requests, namely if requests should
  be stored in the memory cache, split in smaller data chunks and,
  in the case of images, saved on disk in the persistent image
  cache. The request affects all the X messages until the proxy
  is further configured.

- Enabling and disabling loading and saving of persistent images
  due to a X_NXSetCacheParameters is still to be implemented.

- Implemented font channel compatibility with older versions. If
  the font port is queried and the remote proxy doesn't support
  the tunneling of font server connections, an empty string is
  returned.

- The option 'resize', used by agents, is now silently ignored.
  This solves the TR10C01061.

- Added the missing reference to TR08C000981.

nxcomp-2.0.0-8

- Discarded the first idea of setting the font path implicitly in
  the X server side proxy, by means of a multi-pass operation and
  added the NXGetFontParameters() request and reply. If the proxy
  has been configured accordingly, the request returns the X font
  path that can be set by the agent to tunnel the font server con-
  nections through the NX link.

- Changed the parsing of the font server port to be able to handle
  the defaults.

nxcomp-2.0.0-7

- More work on tunneling of font server connections.

- The synchronization requests are now replied at the same time
  as a new request is received, by checking if the channel has
  already gone past the awaited sequence number. This avoids the
  delay caused by the previous versions in the case the expected
  reply had been handled asynchronously, inside the write loop.

nxcomp-2.0.0-6

- The display is again passed to the client using the -display
  parameter.

- The option 'type' is now ignored at X server side. Support at
  the X server side had been left for compatibility with older
  versions of the proxy.

- Added direct support for more session types, namely 'unix-cde',
  'unix-xdm', 'unix-console', 'unix-default'. The 'unix-console'
  and 'unix-default', similarly to 'unix-application', will now
  trigger the 'raw' mode.

nxcomp-2.0.0-5

- Renamed Png.h and Png.cpp to Pgn.h and Pgn.cpp to avoid name
  clashes on Windows.

- The distclean target now removes the autom4te.cache directory.

nxcomp-2.0.0-4

- Added the 'kill=n' option to let the proxy add the process to
  the list of daemons that must be terminated at session shutdown.
  Multiple 'kill=n' options can be specified. The proxy will send
  to each process a SIGTERM signal before exiting.

- Removed the code that forcibly disabled the RENDER extension on
  Solaris. Eventual compatibility problems will be now handled in
  the NX agent.

- The path to the client executable is now assumed to be in the
  NX_CLIENT environment. If the variable is not set, the proxy
  will guess the location based on the target platform. This is
  part of the FR11C01215.

nxcomp-2.0.0-3

- More code cleanup. Protocol step 5 and cache step 2 are assumed
  by default. This allows us to remove the various channel caches
  that are not used anymore.

- Removed the outdated encodeBegin() and encodeEnd() methods.

nxcomp-2.0.0-2

- Added compatibility with the 1.5.0 and 1.4.0 versions. Protocol
  version older than the 1.4.0 will cause the proxy to drop the
  connection.

- Rewritten the version negotiatiation logic to better handle the
  compatibility between the local and the remote version.

- Removed the conditional code handling the compatibility with
  the protocol encodings from 1 to 4.

- Small adjustments to the session negotiation procedure to give
  more hints in the case of errors. A dialog is now issued if the
  remote proxy drops the connection due to a probable authentica-
  tion failure or when the remote proxy version is not compatible
  with our version.

nxcomp-2.0.0-1

- Opened the 2.0.0 branch based on nxcomp-1.5.0-80.

nxcomp-1.5.0-80

- Fixed a bug that prevented the Unix socket to be created in the
  right directory. This affected the ability of the server to run
  NX sessions without the agent encoding.
  
nxcomp-1.5.0-79

- Solved a bug in the 15 to 16 bpp conversion for RDP sessions.

- Corrected a typo in the PANIC message of Unpack16To24 function.

- Optimized the 16 bpp RDP decompression routine.

nxcomp-1.5.0-78

- Implemented the FR11C01215. The following environment variables
  are checked to determine the location of the relevant NX direct-
  ories:

  $NX_ROOT   The root NX directory is the place where the session
             directory and the cache files are created. This is
             usually overridden by passing the 'root=' option. By
             default, the root NX directory is assumed to be the
             directory '.nx' in the user's home.

  $NX_SYSTEM The directory where NX programs and libraries reside.
             If not set, the value is assumed to be '/usr/NX'.
             Programs, libraries and data files are respectedly
             searched in the 'bin', 'lib' and 'share' subdirecto-
             ries.

  $NX_HOME   The NX user's home directory. If $NX_ROOT is not set
             or invalid, the user's NX directory is created here.

  $NX_TEMP   The directory where the X11 Unix Domain Sockets and
             all temporary files are to be created.

  $NX_CLIENT The full path to the nxclient executable. If the va-
             riable is not set, the nxclient executable will be
             run assuming that the program is in the system path.
             This can be useful on platforms like Windows and the
             Mac where nxclient is located in a different direct-
             ory compared to the other programs, to make easier
             for the user to execute the program from the shell.

  Other environment variables:

  $HOME      The variable is checked in the case $NX_HOME is not
             set, null or invalid.

  $TEMP      The variable is checked whenever the $NX_TEMP direct-
             ory is not set, null or invalid.

  $PATH      The path where all executables are searched, except
             nxclient. If $NX_CLIENT is not set, also the client
             executable is searched in the system path.

  $XAUTHORITY
             This is the file containing the X11 authorization
             cookies. If not set, the file is assumed to be in
             the user's home (either $NX_HOME or $HOME).

  $LD_LIBRARY_PATH
             System-wide library search order. This should be set
             by the program invoking the proxy.

- Extended the usage message to document the relevant environment.

- Made the WaitChild() function interruptible. This allows the user
  to terminate the connection procedure immediately, by sending a
  signal to the proxy process while an abort dialog is shown in the
  foreground. This is part of the solution to the TR11C01216.

- Implementation of the FR11C01215 is not yet complete. The client
  program and the nxauth/xauth are still searched using the previ-
  ous logic. In particular, the NX_CLIENT variable is ignored.
	
nxcomp-1.5.0-77

- Corrected the typo in the alert dealing with VNC authentication
  failures. This solves the TR11C01199.

nxcomp-1.5.0-76

- Added the missing initialization in the client and server proxy
  constructors.

nxcomp-1.5.0-75

- Starting from this version the build procedure will automatically
  create a DLL on Windows.

- Disabled exceptions in the compiled code.

- Disabled run-time type information to further reduce the size of
  the executable.

- Compiling with GCC 4.0.0 and -fno-exceptions produces a warning
  in some files, due to control apparently reaching the end of a
  non void function. This is bogus and has been confirmed to be a
  GCC 4.0.0 bug solved in more recent versions.

nxcomp-1.5.0-74

- Imported changes from nxcomp-1.6.0-4.

- Solved a compilation error on Solaris and MacOSX platforms.

- The 'font' option now accepts either a numeric value (for a TCP
  port) or a 'unix/:port' or 'tcp/:port' specification. In the case
  of Unix ports, we assume that a port specification "unix/:7100"
  corresponds to the "/tmp/.font-unix/fs7100" socket and a port like
  "unix/:-1" corresponds to "/tmp/.font-unix/fs-1".

- An absolute file path is also accepted as a valid socket. This is
  useful to test the forwarding of the font server connection, for
  example by running a normal X client and pointing the socket to
  the X server.

- Protocol step 7 is now only assumed when connecting to a remote
  proxy version 1.6.0 or later.

nxcomp-1.5.0-73

- Use the include files from nx-X11 if the nx-X11/include directory
  is found. The previous configure checked the presence of nx-X11/
  exports/include, that might not be built at the time this library
  is compiled.

nxcomp-1.5.0-72

- Fixed a problem on AMD64 due to the size of the area pointed by
  the argument of NXTransReadable(). The ioctl() requires a pointer
  to an int, at least on Linux. The original _X11TransBytesReadable()
  function simply calls the ioctl() by passing the pointer that is
  provided. Returning the value assuming a pointer to a long crashes
  some applications, among them xterm. Now NXTransReadable() follows
  the same schema of the ioctl() call and stores the result assuming
  a pointer to an int.

nxcomp-1.5.0-71

- Ensured that the NX trasport is destroyed on NXTransExit() even if
  the parent has overridden our signal handlers.

- Added attribute 'noreturn' to NXTransExit().

- Small change to the shutdown procedure to send the "Waiting for a
  further signal" just after the watchdog is started.

nxcomp-1.5.0-70

- Added the definition of protocol step 7. The new protocol step is
  implicitly assumed when activating the font server channel, so that
  NX clients and servers may decide what to do by verifying the patch
  version of the peer software. This makes possible to activate the
  feature without stepping up the 1.5.0 version of the software.

nxcomp-1.5.0-69

- Added the -fPIC GCC flag when compiling on AMD64 architectures.

- Small changes to configure.in to have specific CFLAGS.

- Created a new configure using autoconf 2.59.

- Added the 'mask=n' option to determine how channel ids are distri-
  buted between client ans server. By default, channels whose ids are
  multiple of 8 (starting from 0) are reserved for the client side.
  All other channels can be allocated at the NX server side.

- A check is missing on the protocol supported by the remote side,
  so it is likely that mixing this version with older 1.5.0 will not
  work.

- The release has the debug logs enabled.

nxcomp-1.5.0-68

- Added provision for opening new channels on both client and server
  side. This required small changes to the way channel ids are mapped
  and retrieved, so that both sides now support bidirectional mapping
  of file descriptors to channels.

- Made the code handling allocation of new generic channels to reside
  in the base Proxy class.

nxcomp-1.5.0-67

- Renamed the 'embedded keyboard' channels as 'aux' channel.

- Renamed 'samba' channels as 'smb'.

- The 'samba' and 'smb' options can now be used interchangeably. The
  same applies to the 'keybd' and 'aux' options, used to set up the
  auxiliary X channel.

- Added a new font channel. The channel is used to forward X font
  server connections from the X server on the NX client to the remote
  NX server. The channel is not yet functional and requires change to
  the channel allocation mechanism.

- Added a common interface to create new listening sockets. This is
  currently used for additional services, but not for the X display
  sockets.

- Simplified the interface used to accept new connections to channels 
  being forwarded.

- Removed the -V option as nxproxy is not using dlopen() anymore.

- Removed the inclusion of ClientChannel.h in Proxy.cpp that caused
  test symbols to be reverted to undefined.

nxcomp-1.5.0-66

- Made failures setting the IPTOS_LOWDELAY on the proxy socket to
  cause a warning, instead of an error.

- Made the clean target delete the Cygwin specific libraries.

- Updated the configure and Message.h to deal with GCC 4. Solves the
  TR08C000981.

nxcomp-1.5.0-65

- Removed the warning issued on parsing the agent option 'rootless'.
  Solves the TR08C00959.

- MacOSX 10.4 defines socklen_t. Made the definition conditional so
  that we can still support older versions. Solves the TR07C00926.

- Updated the ChangeLog to include references to the solved TRs.

nxcomp-1.5.0-64

- Imported the 1.6.0 changes in the maintenance 1.5.0.

- Removed a wrong assertion that might cause the session to fail
  when the software was compiled with TEST enabled in Proxy.cpp.

- The nxclient dialog process is signaled with SIGKILL on Windows,
  as the SIGTERM is ignored. This solves the TR07C00929.

- Ensured the JPEG error flag is always set before jumping out of
  the Jpeg decompression.

- Skipped errors encontered setting the TCP_NODELAY flag on Mac.
  Solves TR08C00940.

- Few cosmetic changes.

nxcomp-1.5.0-63

- Ensured that the parent is checked often in the keeper process,
  so that, in the case of a premature death, the child is exited
  earlier.

nxcomp-1.5.0-62

- Some performance tuning of the LAN and WAN link modes.

nxcomp-1.5.0-61

- Fixed the problems arisen with loading or saving the image files
  on Windows by forcing the streams to be opened in binary mode.
  These problems have been triggered by the recent Cygwin upgrade.

- Removed the logs that had be left enabled for test purposes.

nxcomp-1.5.0-60

- Made all errors encountered while unpacking an image just print
  a warning in the session log. Such errors are not fatal but the
  client monitors the state of the session at startup, so that by
  marking image decompression errors as such may cause the session
  to be aborted.

- Marked as warnings also errors encountered by trying to load an
  image from disk.

nxcomp-1.5.0-59

- When detected, the CTRL+ALT+SHIFT+ESC sequence is removed from
  the event stream.

- Also modified the message in the session log to issue a warning,
  instead of an error.

nxcomp-1.5.0-58

- Added a setjmp() before yielding the control to the JPEG library.
  This makes possible to recover from the JPEG decompression errors
  that were previously fatal.

- In the commit split request, the client id is now encoded by the
  client channel beside the propagate flag. The client id is igno-
  red by the decoding party. As in the old protocol versions, the
  committing client is taken from the client id that was originally
  sent together with the packed image.

- Fixed the compilation problem when defining OPCODES in Misc.cpp.

- Skipped the synchronous flush of the proxy link when connecting
  to a previous NX version.

- Ensured that the new alerts are only requested when connected to
  a compatible proxy.

- Ignored the option 'fullscreen', targeting the agents.

nxcomp-1.5.0-57

- Added more alerts and changed the name of those dealing with the
  resume of a session.

- Added the MIXED define. When set, the proxy will let all logs go
  to the standard error. This is useful to interleave the Xlib log
  output with the proxy output in a single file.

- Added a new alert to report an I/O error at agent reconnection.
  This is one of those alert that can't be actually shown, but are
  included to offer a consistent view to the agent implementation.

nxcomp-1.5.0-56

- Added the split mode NXSplitModeSync. By selecting this mode,
  the proxy will try to empty the split store immediately, until
  all messages marked in such mode will be synchronized. The im-
  plementation is left to future versions.

  #define NXSplitModeSync     3

- Added the messages specific to RDP and VNC sessions in NXalert.h.
  Included are also a few alerts related to changes to the color
  depth and desktop geometry that may be eventually mandated by the
  remote server.

- Corrected a typo in NXalert.h

nxcomp-1.5.0-55

- Added the 'mode' field in the X_NXStartSplit request. It determi-
  nes the strategy that the proxy will adopt to handle the image.
  If set to 'eager', the proxy will only split the messages whose
  size exceeds the split threshold (the threshold can be found in
  the X_NXGetControlParameters reply). If mode is set to lazy, the
  proxy will split any image that it is not able to find in its
  cache.

  The opcode and the two available modes are defined in NXproto.h,
  currently:

  #define NXSplitModeDefault  0
  #define NXSplitModeEager    1
  #define NXSplitModeLazy     2

- All requests related to image streaming now carry a 'resource' id.
  The id is currently ignored by the proxy in the case of X_NXCom-
  mitSplit requests.

- Added a new NXSetSplitMode() request. It determines the strategy
  that the proxy will adopt to stream the images. If set to 'eager'
  the proxy will only split the messages whose size exceeds the
  split threshold, otherwise it will  split all the images, regard-
  less their size. This is in preparation of the lazy encoding in
  agent.

- Slightly decreased the startup timeout compared to the value it
  had in the 1.4.0. This timeout is used to retain the images used
  during session startup in the persistent cache.

nxcomp-1.5.0-54

- Modified the text of the begin-reconnection alert to mention the
  speed of the connection detected by the agent.

nxcomp-1.5.0-53

- Reworked the handling of the abort-split events issued by the re-
  remote proxy so that we now finalize the procedure and restart the
  client asynchronously, in the middle of the write loop.

nxcomp-1.5.0-52

- Rewritten the internal interface to the notification events. There
  are now five different split notification events:

  NXNoSplitNotify        The operation didn't cause any actual split.
                         The client can be immediately restarted.

  NXStartSplitNotify     A split is ongoing. The client should be
                         suspended until the end of the split.

  NXCommitSplitNotify    A complete request has been recomposed. The
                         client can commit the given request to the
                          X server.

  NXEndSplitNotify       The split operation was duly completed. The
                         client can be restarted.

  NXEmptySplitNotify     No more split operation are pending. The
                         agent can use this information to implement
                         specific strategies, requiring for example
                         that all messages have been recomposed at
                         the remote end. This can include updating
                         the drawables that were not synchronized
                         because of the lazy encoding.

- Removed the X_NXSync and X_NXKarma operations, not used anymore by
  the NX agents.

- Increasing or decreasing a timeout makes it respectively equal to
  the base timeout or to the base timeout / 4.

nxcomp-1.5.0-51

- Improved the mechanism by which synchronization replies are sent
  to the X client proxy.

- Using the leftPad field as passed by the nxagent 1.5.0-58 doesn't
  seem to work with the MIT-SHM. The workaround is to disable the
  MIT-SHM operation in the case of 1 bpp images.

- Removed the limitation on the size of the shared memory segment
  that had been introduced for test purposes.

nxcomp-1.5.0-50

- Solved compilation problem when --with-info was not given.

nxcomp-1.5.0-49

- Improved support for color matching from 15 and 16 bpp to 24 and
  32 bpp in RDP sessions.

- Solved TR05C00910. This was about "shadows" that might appear in
  RDP sessions when small elements like tooltips were drawn.

nxcomp-1.5.0-48

- Added a 'commit' field in X_NXCommitSplit request. When zero, the
  X server side proxy will unlock the message in the message store,
  without actually committing the image to the X server. The new
  field required changes to the encoding. This means that this ver-
  sion is not compatible with older 1.5.0 nxcomp releases.

- Added a new control message. This is used by NXTransFlush() to for-
  ce a roundtrip between the proxies and speed-up the handling of
  the synchronous replies.

nxcomp-1.5.0-47

- Made the timeouts dynamic, based on the user input and the current
  bitrate.

- Set the available tokens to 8. This allows for 16 KB to be sent on
  a modem before having to wait for a reply.

- Added provision for removing a dialog on the remote end. This can
  be used, for example, to get rid of a message that was displayed
  by the agent at the beginning of a lengthy operation.

- Fixed a fault that arose when trying to run the proxy on a display
  whose name began with the 'nx' string.

- Running a client or server session on a display host beginning with
  'nx' should be now possible.

- Flush is now always immediate when there is already data queued in
  the TCP socket.

nxcomp-1.5.0-46

- Created the NXalert.h header from Alert.h to share the alert codes
  with the agents. The new NXTransAlert() interface can be used to
  start an alert on the remote side.

- Created the NXTransParse*() and NXTransCleanup() wrappers.

- Temporarily using the single-dash style when passing parameters to
  nxclient until the double-dash style is fixed.

nxcomp-1.5.0-45

- Motion events are now flushed at the time the X server channel is
  sending the token reply.

- Renamed NXDialog() to NXTransDialog() and added a window ID parame-
  ter, to be used by the agent when starting the "pulldown" dialogs.

- Also renamed the other NX utility functions.

nxcomp-1.5.0-44

- Solved a bug that prevented auxiliary X connections from working
  with the agent.

- Added the missing check on the proxy pointer in HandleTimer() as
  it may be actually called before the proxy is created.

nxcomp-1.5.0-43

- Started tuning the performance. For now, the available tokens are
  set to an improbable value of 10000.

nxcomp-1.5.0-42

- Disabled the X server side remote expose events for test purposes.
  This is intended uncover the display problems introduced by the
  new handling of exposures in the X11 agent.

- Fixed some timestamp related functions to avoid rounding problems.

- Moved the timestamps of split, frame and flush from the Control
  to the Proxy class.

- Made the X server side proxy to skip updating the counters related
  to token management.

- Made also the X server side use deferred flushes.

- Modified handleFrame() to manage both pings and data frames and
  send the token before the actual write operation.

- Cleaned the pseudo-files used to load the control parameters.

- Cleaned up the FIXME's in the lower layers. More FIXME's remain in
  the frontend classes.

- Added a further counter to the statistics tracking the number of
  network writes performed on the proxy link.

nxcomp-1.5.0-41

- Now the watchdog process doesn't kill the parent. The termination
  event is determined by monitoring the child. This is advisable to
  avoid interfering with the signal handling in agent.
 
- The house-keeping process is not started if differential compres-
  sion (and thus caching of images) is disabled.

- Wait for the watchdog to terminate before starting the house-keep-
  ing process.

- Fixed the problem of gray stripes in white areas when using 15bpp
  RDP compression. This solves the TR06C00916.

- Added a log in Message.cpp to tell when an image is removed from
  the memory cache.

- Removed most of the logs. Only left the logs directly related to
  the deferred flushes.

- Removed a warning due to a missing definition in NX.h.

nxcomp-1.5.0-40

- Added the signal '12' to the set of blocked signal on Cygwin. This
  is what is delivered to the application when it tries to create a
  shared memory segment when the cygserver is not running. The call
  later returns "Operation not implemented", only useful if you have
  survived to the signal.

- Modified the configure script to not link against cygipc.

- Improved error handling in the negotiation phase.

- Reset the last signal received when aborting a connection attempt.
  Not doing that might cause a warning.

nxcomp-1.5.0-39

- Both channels and proxy can now deal with incomplete messages by
  waiting for the full data to become available. This is not going
  to work when the transport is connected to an agent that is run-
  ning in-process, so the timeout must be really small.

- Made the main loop more compact by letting a single function read
  from proxy and channels. The same change applies to writing to
  descriptors that are reported to be ready.
  
- Optimized the loop to report as ready the agent descriptors that
  have become available after the proxy execution phase. 

- Now the proxy will try to asynchronously read from its descriptor
  after having read from the channel.

- Unified the routine setting the routines setting the read and write
  descriptors and the timeouts.

- Unified the routine handling the channel events.

- Reintroduced the last ping timestamp to avoid sending more than a
  single ping every PingTimeout milliseconds.

- The cleanup procedure now waits for the watchdog and house-keeping
  processes to terminate.

- Reverted the change occurred in 1.5.0-35 about the byte-ordering
  problem in decompression of PNG and JPEG images.

- More coding about deferred flushes.

- Relevant debug logs are enabled in the main loop, in the proxy and
  in the channel classes, so use only for testing.

nxcomp-1.5.0-38

- Started the implementation of deferred writes based on the new NX
  transport.

- Solved a problem with the statistics file affecting the Windows
  platform. Basically it seems that Cygwin or the stdc++ library
  don't deal correctly with files that are reopened just after
  having unlinked them.

- Implemented support for 15 bpp RDP bitmaps.

- Added "rdpcolors" and "rdpcache" to the list of parameters that
  are ignored in ParseEnviromentOptions().

- This version has lot of logs enabled and some forced cleanups in
  the case of unexpected conditions. Avoid to use it for long-last-
  ing test sessions.

nxcomp-1.5.0-37

- Now splitting of images is fully disabled when running with link
  LAN. Previously the split was not executed by the proxy, but the
  agent was configured to send the start/end sequence.

- Added the check protecting the proxy from token underflow. In the
  previous code the check was left out to verify the conditions un-
  der which this event might be encountered.

- NXTransWrite() and NXTransWriteVector() allocate a context before
  calling handleRead(), so they can correctly return in the case of
  a cleanup.

nxcomp-1.5.0-36

- Modified the channel write loop to interleave abort split events
  between the writes to the X server socket.

nxcomp-1.5.0-35

- Solved a byte-ordering problem in decompression of PNG and JPEG
  images.

- Changed the handleToken() interface to make explicit if a token
  must be issued because of a ping.

- Small fix to prevent a warning in Jpeg.cpp when TEST is enabled.

nxcomp-1.5.0-34

- Solved a few problems introduced by the rewrite of the read loops
  in channels.

- Added definition of NXCollectInputFocusNotify.

nxcomp-1.5.0-33

- Implemented a new control flow system based on tokens exchanged bet-
  ween the proxies. When the clint side runs out of tokens it stops
  sending data until a new token is returned. Tokens are sent whenever
  the data written to the socket exceeds the amount of data set for a
  scheduled write, so the proxy is free to send a number of smaller
  frames before running out of tokens.

- The reason the new system is introduced is because the old method
  had two outstanding problems:

  - It worked very well when the proxies were directly connected,
    but couldn't reliably detect a link congestion when tunneled
    over SSH.

  - In the attempt of reducing the data queued to the TCP layer, it
    didn't leverage all the available bandwidth.

- Moved the final check on the state of the session at the end of
  execution stage, instead of the beginning. The signals sent by the
  user to request the statistics could be reset before the proxy had
  entered the right procedure.

- Added the session type 'unix-rootless', to be used for single apps
  run with the agent in rootless mode.

nxcomp-1.5.0-32

- Modified the main loop to skip the select when I/O is possible on
  any of the agent descriptors or the proxy link.

- Now the house-keeping process is allocated in the heap instead of
  the stack.

nxcomp-1.5.0-31

- The server channel now performs asynchronous reads from the display
  by interleaving them with data decoded from the remote proxy.

- Improved the handling of the memory-to-memory transport.

nxcomp-1.5.0-30

- Redesigned the handling of the congestion events to work more re-
  liably and to report the events to the remote peer earlier.

- Increased the size of the shared memory segment when the MIT-SHM
  extension is activated.

- Solved a bug that prevented the ping timeout to work as expected.

- Ensured that, when entering the main select(), neither the chan-
  nels or the proxy have pending messages in the read buffers.

- There is now only a single case where we can have pending messa-
  ges, namely in the handling of the MIT-SHM events.

- Solved a bug introduced by the 1.5.0-29 that made the proxy en-
  ter the select with a null timeout.

- Renamed LINK_TYPE_AUTO to LINK_TYPE_NONE in NXproto.h.

nxcomp-1.5.0-29

- Now encoding data from the agent descriptors happens in the same
  context as data is written to the buffer.

- Optimized the handling of the congestion events to avoid running
  further unneeded loops.

- Added timer handling utilities.

nxcomp-1.5.0-28

- Added code providing information about the reason of the failure
  encountered connecting to the local X server. This greatly helps
  when troubleshooting X authorization problems.

- On connection failure a warning message is printed in the session
  log.

- Removed the warning that was previously printed when the MIT-SHM
  extension failed to be initialized on Windows. Shared memory has
  problems on Cygwin and it currently doesn't work in NXWin.

- Reworked the message printed in the case of link failure.

nxcomp-1.5.0-27

- Solved a bug in the connection procedure introduced by 1.5.0-25.

nxcomp-1.5.0-26

- Transformed the errors printed on failure of the fork() creating
  the children into warnings. This can happen quite often on Win-
  dows, due to well known Cygwin problems. See also the ChangeLog
  entry for nxcomp 1.4.0-28. This patch closes the TRSL052278 but
  it's obviously not a long-term solution.

- Set the sticky bit when creating the '/tmp/.X11-unix' directory.

- Modified the Makefile.in to remove the *.out.* files generated by
  Valgrind.

- Updated the README files.

nxcomp-1.5.0-25

- Changed the directory where the client for the Mac is searched if
  it is not found in the system path.

- Modified Auth.cpp to use nxauth also on the Mac.

- Reworked the procedure showing the alert dialog when a timeout is
  encountered in the initial connection.

- Removed the experimental code from the official 1.5.0 branch.

nxcomp-1.5.0-24

- Implemented more experimental classes.

nxcomp-1.5.0-23

- Added the NX_SIGNAL_FORWARD action to NXTransSignal(). This can
  be used to let the proxy call the original signal handler of the
  agent after having blocked the signal.

nxcomp-1.5.0-22

- Ensured that we always have a context, even before creating the
  transport.

- Suppressed the error message printed when passing the -h option.

- Added the experimental code that is currently under development.

nxcomp-1.5.0-21

- Enabled the fake X cookie authentication. This requires checking
  the remote proxy version to verify that the server supports the
  new authorization mechanism.

- It's worth noting that the X client side proxy doesn't care which
  cookie is sent over the connection. The problem is that clients
  connecting to 1.4.0 servers don't have a method to force the ser-
  ver to use the fake cookie. This means that we have to solve the
  problem by letting the proxy check the remote version so that it
  can omit to replace the cookie when connecting to older servers.

nxcomp-1.5.0-20

- Added the NXTransCongestion() function. It returns true if proxy
  is in congestion state.

- Removed an incorrect warning that was printed when calling force()
  for the memory-to-memory transport. The agent could actually re-
  quire multiple loops to read all data queued for it.

nxcomp-1.5.0-19

- Small optimization in NXTransReadable() to run a new NXTransConti-
  nue() loop only after at least RetryTimeout milliseconds are pas-
  sed since the last call and still no data is available. This cuts
  the number of unneeded loops to 1/4th of the total, probably more,
  on faster machines.

- Added NXCollectGrabPointerNotify to NXproto.h.

nxcomp-1.5.0-18

- Minor changes to NXTransContinue().

nxcomp-1.5.0-17

- Moved respawning of a new nxclient instance in the cleanup procedu-
  re. This ensures that the respawn is executed whatever is the rea-
  son of the session shutdown.

- Added a method to force closure of a given channel in proxy.

- Removed code handling the special case triggered on Windows by the
  presence of a NX_SESSION variable in the environment.

nxcomp-1.5.0-16

- Added the NXTransSignal() function to let agents tell to the proxy
  how to handle the standard POSIX signals. Given the SIGINT signal,
  for example, the caller can specify any of the following actions.

  NX_SIGNAL_ENABLE:  A signal handler will have to be installed by
                     the library, so that it can be intercepted by
                     the proxy.

  NX_SIGNAL_DISABLE: The signal will be handled by the caller and,
                     eventually, forwarded to the proxy by calling
                     NXTransSignal() explicitly.

  NX_SIGNAL_RAISE:   The signal must be handled now, as if it had
                     been delivered by the operating system. This
                     function can be called by the agent with the
                     purpose of propagating a signal to the proxy.

  As a rule of thumb, agents should let the proxy handle SIGUSR1 and
  SIGUSR2, used for producing the NX protocol statistics, and SIGHUP,
  used for disconnecting the NX transport.

- The following signals are blocked by default upon creation of the
  NX transport:

  SIGCHLD    These signals should be always put under the control
  SIGUSR1    of the proxy. If agents are intercepting them, agents
  SIGUSR2    should later call NXTransSignal(..., NX_SIGNAL_RAISE)
  SIGHUP     to forward the signal to the proxy.

  SIGINT     These signals should be intercepted by agents. Agents
  SIGTERM    should ensure that NXTransDestroy() is called before
             exiting, to give the proxy a chance to shut down the
             NX transport.

  SIGPIPE    This signal is blocked by the proxy, but not used to
             implement any functionality. It can be handled by the
             NX agent without affecting the proxy.

  SIGALRM    This is not blocked by the proxy, but could be used
             in future.

  SIGVTALRM  These signals are not used and should not be used in
  SIGWINCH   future versions of the library.
  SIGIO
  SIGTSTP
  SIGTTIN
  SIGTTOU

- By calling NXTransSignal(..., NX_SIGNAL_DISABLE) nxcomp will res-
  tore the signal handler that was saved at the time the proxy hand-
  ler was installed. This means that you should call the function
  just after the XOpenDisplay() or any other function used to init-
  ialize the NX transport.

nxcomp-1.5.0-15

- In NXTransContinue(), if the transport is gone, return immediately,
  that is without having to wait until the NXTransSelect() timeout.

- Ensure that NXTransCreate() has a jump context, just in the case
  a subsequent operation would cause a cleanup.

nxcomp-1.5.0-14

- Solved a problem with requests left in the agent's buffer when run-
  ning the NX transport. The agent could have enqueued data to our
  side and checked the available events but requests could not be
  written to the proxy because proxy might not have had a chance to
  enter a new select. We found that this behaviour was triggered by
  _XEventsQueued, so now a new loop is forced when agent is calling
  _X11TransDataReadable. The procedure can be optimized, by avoiding
  an expensive loop when no critical I/O is pending.

- Added a few additional logs to ClientChannel and ServerChannel.

nxcomp-1.5.0-13

- Added the code handling the special cases of an user not specifying
  a proxy cookie or the case of the X authorization file not contain-
  ing a value matching the display. In the first case we'll forward
  the same cookie that was feeded to the proxy, in the second case we
  will forward to the X server a random generated cookie, similarly to
  what SSH does in this same condition.

- Rewritten the command line parser. Removed all the command line
  options parsed on behalf of nxproxy except:

  -C          Specify that nxproxy has to run on the "X client"
              side, listening for connections and impersonating
              an X server.\n\

  -S          Specify that nxproxy has to run in "X server" mode,
              thus forwarding the connections to daemons running
              on the client.\n\

  -V n.n.n    Request nxproxy to load the given nxcomp version.
              This option is only present on Solaris and Linux.

  -v          Print version information.

  host:port   Put at the end, specifies the host and port of the
              listening proxy.

  value=name  Set the NX option to the provided value.

  Multiple NX options can be specified in the DISPLAY environment or
  on the command line, by using the nx/nx,name=value notation.

- The above information is printed on the console when incurring in
  a parse error, together with a list of the available option=value
  parameters.

- Renamed the 'log' option to 'errors'. This makes sense as the de-
  fault name for the log file is actually 'errors'.

- Now the "Established X server connection" message is printed to
  the session log only after the X connection has passed the X auth-
  entication phase. This means that the NX client should become able
  to show the details of the session log whenever the session fails
  due to a cookie problem.

- When selecting the additional services without specifying a port,
  the client proxy will now automatically forward the connections to
  the corresponding well-known ports of the CUPS, SMB and HTTP servi-
  ces. Embedded X keyboard connections will be automatically forward-
  ed to the same display port used to connect to the X server. The
  user will still have to specify the port to be used for the media
  connections as we don't have a suitable well-known port.

- Starting from this version, connections to the keybd port will cre-
  ate real X connection channels. This is required to let connections
  leverage the fake authorization cookie.

- By testing the forwarding of keybd connections I found that, when
  letting X clients connect to the port, it is required to provide
  the X cookie for the unix display. Adding only the TCP cookie will
  not work. For example, by creating a cookie as in:

  xauth add localhost:2009  MIT-MAGIC-COOKIE-1  6f...f4

  And running:

  xterm xterm -display localhost:2009

  You will get the following error:

  Xlib: connection to "localhost:2009.0" refused by server
  Xlib: No protocol specified

  Adding also the unix cookie will fix it:

  xauth add localhost/unix:2009  MIT-MAGIC-COOKIE-1  6f...f4

  This seems to be a Xlib problem, with Xlib trying to get the cookie
  for the UDS port even if the TCP port was requested by the user.

- Fixed a bug that prevented the nxclient dialog to be displayed when
  the session was abruptedly shut down.

- Fixed the compilation error on Apple MacOSX due to the sa_restorer
  field in sigaction. As long as this field is present on Linux we
  will keep following the safer route and will set it explicitly to
  NULL.

- Included what needs to be included in Process.cpp to compile with
  older gcc.

nxcomp-1.5.0-12

- Implemented a replacement for the popen() and pclose() that do not
  rely on a shell to run the command. They were required on Windows,
  where we don't ship a suitable shell in the install.

- Removed code forcing the PATH to include the bin directory on
  Windows.

nxcomp-1.5.0-11

- Forced Auth.cpp on Windows to have the directory containing the
  nxauth executable in the PATH. This is just for testing, until
  nxclient is fixed.

- Fixed compilation errors on Cygwin and Sun.

- Removed the NX_FORCE_* stubs.

nxcomp-1.5.0-10

- Modified the memory management policies in ReadBuffer to fit all
  the available bytes in a single buffer allocation.

- The locateMessage() methods now give hints on the amount of data
  that has to be read.

- The read loop in channel now doesn't yield in the case of prio-
  ritized messages. This is experimental.

- Removed the check on isTimeToYield() between encodings of multi-
  ple messages. This is aimed at reducing the risk of leaving pen-
  ding messages in channels.

- Modified the channels' read loop to always read all the available
  data.

- Disabled the log output that was selected when compiling with the
  configure option --with-info. This leaves space for other log out-
  put to be selected for more up-to-date scopes.

- Implemented the NXTransReadVector() and the NXTransWriteVector()
  functions to replace READV() and WRITEV().

- Implemented memory-to-memory communication between the agent and
  the NX proxy by making use of the NXTransAgent() interface in the
  nx-X11/lib/X11/Xtranssock.c file.

- Added a check in NXTransSelect() for the EBADF and, on Solaris,
  the EINVAL errors. It can happen in the X11 code that a descript-
  or has become invalid before it is removed from the managed set 

- Rewritten the signal handling functions to restore the old actions
  and masks when the NX transport is destroyed.

- Added a NXTransAgent() function to let agents tell the proxy which
  descriptor must be used for the controlling connection. Setting a
  controlling connection has the effect of disabling further X client
  connections and makes the proxy terminate when the channel is shut
  down.

- Solved a problem with setting the initial timeout in the select().

- Modified the Makefile.in to not include -Wno-deprecated when compi-
  ling C programs.

nxcomp-1.5.0-9

- Fixed a problem that prevented the 1.5.0-8 to work on the NX server
  side.

- This version has NX_FORCE_NULL_LISTEN_OPTION and NX_FORCE_NEW_SES-
  SION_OPTION undefined, so it should work in a way that is compati-
  ble with the old nxcomp.

nxcomp-1.5.0-8

- The new code comes with a preliminary integration of nxcomp with
  SSH. It is now possible to create the NX transport by just calling
  the "switch" command as in the following example:

  NX> 299 Switching connection to: NX options: ...

- Other possible forms for the NX switch command are:

  NX> 299 Switching connection to: NX mode: ...

  NX> 299 Switching connection to: NX mode: ... options: ...

  Or just:

  NX> 299 Switching connection to: NX

  The "mode" parameter is there to provide a way to run both enc-
  rypted and unencrypted connections. Possible values are "encrypt-
  ed", "unencrypted" or "default", the latter being an alias for
  "encrypted". Unfortunately I was not able to test unencrypted
  connections, so this may or may not work.

- The top-level process can create the NX transport layer by calling
  NXTransCreate(). The user has to set up a socket pair and pass the
  higher descriptor to nxcomp. nxcomp will later monitor its end, by
  reading and writing NX-encoded traffic. The user has to call the
  NXTransExecute() function as often as it is possible, by letting
  first NXTransPrepare() combine the sets of NX descriptors with the
  descriptors that are used inside its process. A custom NXTransSel-
  ect() is provided to optionally replace the original select(). This
  function saves the original error code and the number of selected
  descriptors upon exit, so the user can call it, restore the original
  values as they were returned by the select() and run the rest of
  the loop unmodified.

- Future versions of the library should provide appropriate methods
  for passing data to and from the proxy by means of a memcpy(), so
  that it will be possible to remove the even minimal TCP overhead.

- Note that integration is far from complete. More work is required
  especially to manage the shutdown cleanly, in a way that gives to
  SSH a chance to free its resources, and on adding facilities for
  handling SSH and NX signals in a single function.

- Rewritten the initialization procedure to make possible to run the
  proxy in-process in an arbitrary connection manager, like SSH or a
  HTTP utility. The same functionality can be used to embed nxcomp in
  the NX agents, so that nxcomp has not to run in a separate process.

- A new state-machine handles the advances through the connection
  stages until the remote proxy (or the forwarder process ) is auth-
  enticated, options have been negotiated and the session is started.

- The option "session" is now used to pass the name of the session
  file to the proxy. The parameter was previously used to pass the
  literal name of the session, as set by the user, and was ignored
  by the proxy. By default the session log is the standard error of
  the process. It is anyway required to set the option when running
  inside SSH, otherwise output will go to the same file as the SSH
  output. In the NX client this would be the 'sshlog' file.

- This version can be easily crafted to test the new integration by
  setting the following define:

  NX_FORCE_NULL_LISTEN_OPTION

  This makes possible to test the nxcomp/nxssh integration by using
  any production 1.4.0 client. To run this version you are required
  to use nxproxy 1.5.0-4 and nxssh-1.5.0-6.

- New functions handling enabling and disabling signals, based on
  sigprocmask().

- Improved error reporting when failures are encountered while ne-
  gotiating the session.

nxcomp-1.5.0-7

- Caches are saved with a version identifier 1.4.0 so that they are
  not discarded after upgrading the software to the 1.5.0.

- Made values of T_* enumerations to be all lower case.

- Updated copyright to year 2005.

- Started working on an interface for running nxcomp in-process, as
  a additional transport layer of nxssh or nxagent.

nxcomp-1.5.0-6

- Modified the configure script and the makefiles to not include the
  -Wstrict-prototypes and -Wmissing-prototypes compilation flags. The
  -Wnested-externs and -Wmissing-declarations flags are not included
  when using GCC 3.

- Removed the initial newline from string "NXPROXY - Version" printed
  at program startup.
  
- Made X authentication compatible with 1.4.0 clients. This is a tem-
  porary solution while code is updated to handle the new X authori-
  zation scheme.

nxcomp-1.5.0-5

- Added an Auth class to handle the X authentication. The NX server
  should now use the same proxie cookie that is passed by the client
  at session startup. The X server side proxy will forward the autho-
  rization credentials by replacing the fake cookie with the real co-
  okie, as it is read from the auth file using the xauth utility. The
  implementation is based on the corresponding code found in the SSH
  client and comes with the same limitations: only MIT-MAGIC-COOKIE-1
  cookies are checked and the authorization file is read only once,
  at the time the instance is initialized. If the auth file changes
  along the life of the session, the old cookie will still be used.
  This works with X servers because of an undocumented "feature".
  See also nx-X11.

nxcomp-1.5.0-4

- Adjusted for alarm(0) returning an inconsistent value in ConnectTo-
  Remote().

- Small changes to Types.h, Jpeg.cpp and Png.cpp to compile with gcc
  3.4.2.

- Cosmetic changes to the ChangeLog file.

nxcomp-1.5.0-3

- Removed test code from ServerChannel.cpp.

- Small cosmetic change in Loop.cpp.

- Tested for compatibility against 1.4.1-8.

nxcomp-1.5.0-2

- Changed VERSION file according to TRCL052336.

nxcomp-1.5.0-1

- Opened the 1.5.0 branch based on 1.4.1-9.

nxcomp-1.4.1-9

- Implemented methods PACK_RDP_PLAIN_64K_COLORS and PACK_RDP_PLAIN_-
  16M_COLORS. It seems that 16 bpp plain bitmaps can be seldom recei-
  ved. This doesn't seem to be the case of 24 bpp bitmaps.

nxcomp-1.4.1-8

- The new code enables use of 16 bpp and 32 bpp RDP bitmaps. This re-
  quired modifications to the following files:

  Misc.h
  Misc.cpp
  Loop.cpp
  Control.cpp
  ServerChannel.cpp
  Unpack.h
  Unpack.cpp

- Lots of cosmetic changes compared to the original code in 1.4.1-7.

- Merged the 1.4.0 and the 1.4.1 branches by importing changes up to
  the 1.4.1-7.

nxcomp-1.4.0-30

- Modified the function checking the Unix socket where X connections
  will be forwarded. The function will not fail if the socket itself
  doesn't exist yet. This solves the TRCL042203.

- Moved the code checking for the CTRL+ALT+SHIFT+ESC sequence to a
  separate function. The implementation will now look for a different
  sequence on the MacOS/X platform. This should solve the TRCL042182.

nxcomp-1.4.0-29

- Solved a bug that could cause proxy to stop reading data from the
  X channels due to an incorrect calculation of the bytes queued on
  the proxy link. The bug only affected Linux kernels of the 2.0/2.2
  series.

- Fixed a problem in the proxy class that could let the select time-
  out to become zero.

nxcomp-1.4.0-28

- Prevented the main proxy process from quitting when the fork() of
  any of the children fails. This can actually happen on Windows due
  to conflicts in reallocating any of the Cygwin DLLs.

- Reworked handling of the priority flag in channels when dealing
  with the X_InternAtoms and X_AllocColor requests to reduce the time
  of session startup. Priority is never set in case of X_InternAtom
  requests and replies as we assume that most clients use the appro-
  priate Xlib function to pipeline multiple requests in a single net-
  work operation.

- The timeout after which proxy will abort the peer connection is
  still 120 seconds. An alert dialog will be shown earlier, after 30
  seconds instead of 60.

nxcomp-1.4.0-27

- Removed the code setting priority on channels on ButtonPress and
  Button release events. It seems preferrable to delay the flush and
  pack more events in a single frame. This makes possible to get the
  ButtonRelease together with the ButtonPress.

- Fixed error detection in SetNoDelay() where a positive result
  could produce a 'not supported' message in debug mode.

nxcomp-1.4.0-26

- Reworked the check aimed at detecting the clock drifts. The previ-
  ous code, introduced in 1.3.2-2, had the undesired side-effect of
  resetting the proxy timeout. This could cause the proxy to never
  detect that the other end had been killed.

- The default behaviour of proxy is now to terminate the session at
  the time an error is encountered. This includes network failures.

- Added a new dialog to be shown to the user whenever the session
  is terminated abnormally.

nxcomp-1.4.0-25

- Fixed a bug in handling of suppression of errors generated by
  committing the image splits. Other errors, unrelated to the commit
  of split, could be suppressed. This might cause the hangup of the
  session when the suppressed error was matching a reply.

nxcomp-1.4.0-24

- When killing the proxy process -9 the watchdog could remain alive.
  This caused the SSH link to keep the stderr open, with the effect
  that former proxy message were not flushed to the session log.
  Now the watchdog checks every second if the parent is dead, so
  that file descriptors can be closed as soon as possible.

- SetupDisplaySocket() tried to force the connections to the X
  server on the UNIX port whenever the display was set to localhost.
  This patch was intended to fix a bug in nxclient, using the TCP
  port even when the display was set to a UNIX socket. This beha-
  viour caused problems when running nxclient on a remote host by
  means of a ssh -X. Proxy will now adhere to the display setting.

nxcomp-1.4.0-23

- Added the possibility to respawn nxclient at the end of session.
  This is an useful feature when powering thin-clients where NX
  is the only application made available.

- This configuration applies system-wide to the local client ins-
  tallation. By default it is disabled. It can be enabled by the
  by creating a 'noexit' file in the directory '/usr/NX/share',
  or at compile time, by setting ENABLE_RESTART_ON_SHUTDOWN to 1.

- Note that the solution is not perfect yet, as there are cases
  where session could die without going through HandleShutdown(),
  for example if a decoding error is raised in the communication
  with the remote peer and the subsequent restore of the proxy
  link fails to succeed.

nxcomp-1.4.0-22

- Corrected typos in Timestamp.h and Loop.cpp.

nxcomp-1.4.0-21

- Tuned the handling of RenderCompositeGlyphs. Now compression of
  RENDER shows an average ratio of 8:1. This is a steady increase
  compared to the 5:1 of the 1.3.2 version. The overall advantage
  when running clients displaying a large amount of text is 30%.

nxcomp-1.4.0-20

- Added a new message store for the CreatePixmap request.

- Fixed handleCopy() to only send the data part past the offset.
  This fix can save a significant amount of traffic, especially
  when sending many small images whose size doesn't reach the
  threshold set for compressing them.

nxcomp-1.4.0-19

- Added tuning of all the RENDER requests. RenderCompositeGlyphs
  will require further work.

- Completed porting of the RENDER requests to the new templates.

nxcomp-1.4.0-18

- Tuned the handling of RenderCreatePicture and RenderFreePicture.

- Created a new template system for writing new message encoders.

- Renamed getBits() in EncodeBuffer with diffBits(). The getBits()
  method now returns the bits actually allocated in the buffer and
  can be called multiple times.

nxcomp-1.4.0-17

- Provided specific encoding of the remaining RENDER requests and
  added compression of RenderCreateGlyphSet.

nxcomp-1.4.0-16

- Code underwent through 7 different patch versions but seems to
  be stable now. It still needs to provide specific encoding for
  RenderCreatePicture RenderChangePicture and RenderFreePicture.
  Code will likely include incompatible changes at any new version
  until the new encoding will stabilize, so be sure that you use
  the same nxcomp version at both sides.

- Created the infrastructure for compressing extension messages
  based on the minor opcode. A new class, MinorMessageStore, has
  to be inherited by stores requiring specific compression, so
  that all the encoding methods of the parent can be redirected
  to it. The RENDER extension is now compressed using this new
  class.

- Managed to maintain the compatibility with caches created by the
  1.3.X version. Caches will be saved using the old format if the
  remote version is not a 1.4.x. When restoring a cache created
  by the 1.3.x with both proxies being the newest version, RENDER
  mesages will be discarded without having to discard the whole
  cache.

- Added a member to the message class to store the identity size.
  This field is now used instead of the default data offset to
  manage the message data, that is the part of message after the
  identity.

- Removed the warnings printed in the session log when passing the
  'kbtype' and the 'geometry' options to the proxy. These options
  are actually used by agents.

nxcomp-1.4.0-15

- Started implementation of the new framework for handling enco-
  ding of X extensions.

- Renamed the overloaded methods handleEncode() and handleDecode()
  to handleEncodeCached(), handleEncodeIdentity() and handleDecode-
  Cached(), handleDecodeIdentity().

- Updated the copyright notice to year 2004.

nxcomp-1.4.0-14

- Added the new channel for HTTP connections. This channel can be
  used to let applications running on the NX server get access to
  data and applications made available by a HTTP daemon running at
  the client side.

  This channel is not used at the moment by nxclient. It can be
  activated by passing http=1 to the NX server side proxy and the
  value http=80 to the NX client side.

nxcomp-1.4.0-13

- Quick patch to run on MacOS/X where inet_addr("127.0.0.1")
  alone seems to fail to return a valid interface.

nxcomp-1.4.0-12

- Few cosmetic changes to logging.

- Removed the debug output.

nxcomp-1.4.0-11

- Removed code used for simulating the new forwarding function-
  ality without client and server support.

nxcomp-1.4.0-10

- Implemented authentication of the forwarder to the listening
  proxy. If a session cookie is required, the forwarder must
  provide the cookie upon connection.

  An authentication phase at the time the forwarder connects
  to the NX client side is strongly suggested because it is usu-
  ally this side that sends the authorization cookie. Without
  such a forwarder authentication, the local peer would reveal
  the cookie to the first process connecting to the port.

- If no cookie is specified in the switch command, the forward-
  er is required to skip the authentication phase. This can be
  useful when running the programs on the command line.

- The implementation required appropriate changes to session
  negotiation in nxssh. This version requires nxssh-1.4.0-8.

nxcomp-1.4.0-9

- Fixed the startup procedure to correctly negotiate the cookie
  when the X server side proxy is listening for a forwarder.

- When listening for a local forwarder (that is when the listen
  option is enabled at X server side), proxy will listen for the
  forwarder on the localhost interface.

- This version has ports and and other parameters hardcoded for
  testing purposes and is not intended for normal use.

nxcomp-1.4.0-8

- Slightly modified the text of FAILED_PROXY_CONNECTION alert.

nxcomp-1.4.0-7

- Added provision for leaving a running dialog showing an OK box
  if proxy is exiting abnormally. This seems to fail to yield the
  expected results as, at the present moment, client checks if
  parent has exited.

- Added a Binder class invoked when calling proxy with -B option.
  It would serve as a replacement of the modifications I'm doing
  in nxssh. The class is just a framework and the implementation
  is unfinished.

nxcomp-1.4.0-6

- Added a line in the session log if the connection procedure is
  aborted due to a signal.

- Fixed ParseHostOption() to let it take in account the proxy
  port offset when passing 'host:port' as the last parameter at
  X server side.

nxcomp-1.4.0-5

- Lowered the default port offsets used for CUPS and SMB services
  to 2000 and 3000. Arbitrary ports can be used by passing the ser-
  vice's port at proxy startup. By default, anyway, the port is at
  the same offset of the proxied display. Considering that the NX
  server uses to start the first session at display 1000, we must
  lower some of the defaults to avoid interference with the normal
  X sessions run on the server.

  Session at display ":1000" will have:

  . Forwarding of CUPS connections at 3000.

  . Forwarding of SMB connections at 4000.

  . The listening proxy (at NX server side) at 5000. This
    port is not used when enabling SSH tunneling

  . The proxied X display (NX agent or proxy) at 7000.

  . Forwarding of multimedia channels at 8000.

  . Forwarding of embedded keyboard connections at 9000.

- Turned off the log output.

nxcomp-1.4.0-4

- Managed to get the X client side proxy connect to the remote
  peer. This means that some parameters that were implicitly
  assumed based on the proxied port simulating the X display
  must be now specified in the NX display string.

- The 'port' parameter now specifies the remote TCP port where
  the local proxy will connect to the remote peer. In previous
  versions this parameter also affected the proxied port. This
  was mainly a side effect, as the remote peer was always con-
  tacted at port 4000 plus the proxied display offset.

- Added the 'listen' parameter to tell to the proxy that is go-
  ing to accept the peer connection on which port it will be
  contacted. By default, similarly to the previous version, the
  proxy will listen at the proxied display offset.

- A check has been added in order to disallow passing both the
  'accept' and the 'connect' parameter at the same time. A simi-
  lar check affects the 'listen' parameter.

- Renamed the previously unused 'sync' channel as 'cups'.

nxcomp-1.4.0-3

- Preserved the ability of version 1.3.2 to load caches generated
  by this version.

nxcomp-1.4.0-2

- Small fixes to compile under Solaris 8.

nxcomp-1.4.0-1

- Opened the 1.4.0 branch.

nxcomp-1.3.2-4

- Fixed a problem with shmget(). Code in ServerChannel checked
  the return value for being greater then 0, while 0 can actual-
  ly be a valid segment.

- When memory cache is disabled, nxcomp will explicitly set the
  appropriate control variables dealing with loading and saving
  of the persistent cache. This can be considered a cosmetic
  change as nxcomp will disable NX delta compression if memory
  cache is not available and this has an implicit effect on the
  ability to load and save such a cache.

nxcomp-1.3.2-3

- Removed inclusion of zlib.h in Png.cpp. Conflicting symbols
  with zlib.h from nx-X11 could cause compilation to fail.

nxcomp-1.3.2-2

- Added a function to take into account the clock drifts at the
  time we check the ping from the remote proxy. This can be
  caused by the user changing the system time or by small adjust-
  ments introduced by the operating system making the clock go
  backward. Such events could cause the proxy link to be shut
  down and reconnected.

- Reduced the length of lines printed in statistics when showing
  the details of X protocol's opcodes. This is intended to help
  nxclient to keep the whole statistics in the 'details' window,
  so that users don't have to use the scrollbars.

nxcomp-1.3.2-1

- Opened the 1.3.2 branch.

nxcomp-1.3.1-5

- It seems that Solaris can return an EINVAL error selecting a
  shutdown descriptor even before we actually close the socket.
  We now ignore the condition on Solaris. This is definitely a
  Solaris bug. 

nxcomp-1.3.1-4

- Increased the timeout after which proxy will abort the peer
  connection to 120 seconds. An alert dialog will now be shown
  after 60 seconds, instead of the 30 seconds being the default
  in the previous version. Some users reported the timeout to
  be too short in the case of temporary network failures.

nxcomp-1.3.1-3

- Some optimizations in the cache house-keeping process. Now it
  runs at lower system priority in respect to the parent. Any 2
  iterations through directories and images, it also sleeps for
  a tiny amount of time. This further decreases the system load.

- Removed the underline characters and added a colon in the
  title of this ChangeLog to fully comply with format used in
  the release notices.

nxcomp-1.3.1-2

- Fixed a crash when running both client and server on the SPARC
  Solaris. An optimization used to avoid byte-swapping when both
  hosts have the same endianess doesn't work on SPARC if buffer
  is not aligned to word boundary. A better version of the code
  should check the CPU, not the OS, as this probably applies to
  other processors.

nxcomp-1.3.1-1

- Opened the 1.3.1 branch.

nxcomp-1.3.0-50

- Disabled the processor limit in X client side proxy. In previous
  versions the processor load limit was set to an idle time ratio
  of 2. This was likely to cause an unwanted slowdown on very old
  hardware or when running the server as guest OS inside a VMWare
  virtual machine.

nxcomp-1.3.0-49

- Last minute update on proxy shutdown bug on Cygwin. A stack
  trace reveals that faillure happens in the static destructor of
  the BlockCacheSet class. It seems that problem appeared just
  after having upgraded to the latest version of Cygwin DLL. Now
  the destructor is skipped at shutdown.

nxcomp-1.3.0-48

- Further fix to overcome the shutdown problem on Windows.

nxcomp-1.3.0-47

- Used T_files::value_type() in Keeper.cpp. The form without the
  explicit constructor fails to compile with GCC 2.91 on RH 6.2.

- Fixed '==' -> '=' in configure.in to build under RH 6.2 and
  probably other platforms.

nxcomp-1.3.0-46

- The cleanup procedure now skips deletion of the IO streams
  under Windows. This is intended to overcome a strange segfault
  occurring at random time, at the time proxy is being shutdown.

nxcomp-1.3.0-45

- Newer versions of the stdlibc++ do not seem to be able to deal
  with NULL strings or non printable characters. This caused the
  standard error stream to get sometimes corrupted in the case
  TEST and DEBUG logs were enabled in Loop.cpp.

nxcomp-1.3.0-44

- Disabled TEST and DEBUG logs in ServerChannel.

nxcomp-1.3.0-43

- Fixed a crash when unpacking an image in server proxy in the
  case the unpack state for the given channel had not been
  previously created.

nxcomp-1.3.0-42

- Small modification to setSchedule() to not account previous
  data accumulated in the encode buffer. The new code seems to
  allow better use of the available bandwidth.

nxcomp-1.3.0-41

- Further fix in Tight decompression. Content of the main write
  buffer was not removed before flushing the unpacked data to
  the X server link.

nxcomp-1.3.0-40

- Removed the code marked as FIXME in Loop and ServerChannel.
  Code was used in previous version to override any pack method
  other than NO_PACK and to disable initialization of the shared
  memory.

nxcomp-1.3.0-39

- Solved the problem with unpacking of RDP text on big-endian
  architectures. The width field in PutPackedImage was put as
  16 bits and extracted as 32 bits at decoding side.

- Moved the code checking if any of the children has exited in a
  specific function. This function is now called any time signals
  are newly enabled. This works even on Solaris.

- Enabled use of shared memory with Tight image decompression.

- Added event NXCollectPropertyNotify to NXproto.h.

nxcomp-1.3.0-38

- Message locks are now checked before splitting a message.

nxcomp-1.3.0-37

- Added a further counter to yield encoding data if the amount 
  of output bytes to be written to channels exceeds a threshold.

- Modified proxy to write data immediately if the encoding loop
  was interrupted.

nxcomp-1.3.0-36

- Further fix required by Tight decompression. By handling mul-
  tiple writes in the Tight class we may flush the main write
  buffer in the wrong order. If Tight decompression is enabled,
  the buffer is now flushed before decoding the packed image.

- A SIGCHLD is raised any time signals are newly enabled. This
  allows the main loop to wait() the pid of children that had
  exited while signals were disabled.

nxcomp-1.3.0-35

- Fixed Tight decompression by handling multiple writes to the
  channel's transport inside the decompression function.

- Made Tight decompressor in ServerChannel a pointer instead of
  an instance of the class. Class is allocated the first time it
  is referenced.

- Rewritten handleUnpack() in ServerChannel to use a switch()
  on the pack method instead of multiple if().

nxcomp-1.3.0-34

- Disabled RENDER extension when running X agent sessions on
  the Solaris client. Problems seem to be caused by incompati-
  bilities in the implementation of RENDER on the Sun X server
  shipped by default. We did not test NX with the XFree86 X
  server, but it seems that, when using the Sun X server, even
  plain X clients don't make full use of the extension.

nxcomp-1.3.0-33

- Added 4 new fields to the X_NXGetControlParameters reply.
  A dialog should be shown by agent if proxy was not able to
  negotiate a persistent cache or if a cache was selected but
  not loaded because incompatible or corrupted.

- Fixed a bug on Solaris where socket() must be recreated if
  the first connect() fails. Not a problem. The strange thing
  is that if you reuse the socket(), the subsequent connect()
  is successful and the program fails as soon as you try to
  write to it.

nxcomp-1.3.0-32

- Added request X_NXFreeUnpack to free the resources allocated
  by the remote proxy to unpack images for the given agent's
  client

- Added an alert at X server side if proxies were not able to
  negotiate a persistent cache or if a cache was selected but
  not loaded at X server side (that means that probably cache
  was not compatible or corrupted). The alert is not enabled
  at the moment. Before enabling it, we need to find a way to
  deal with full-screen mode.

- Tuning of MIT-SHM parameters.

nxcomp-1.3.0-31

- Modified the following requests to carry the id of the
  agent's client:

  - X_NXSetUnpackGeometry
  - X_NXSetUnpackColormap
  - X_NXSetUnpackAlpha
  - X_NXPutPackedImage

  Now each agent's client has its own record pointing to the
  geometry, colormap and alpha channel that will be used to
  unpack the image. Code is not finished yet so it is advisable
  that agents' writers keep using client id 0. Note also that
  the final solution will require some changes to the way split
  notifications are sent to agent that I plan to implement in
  the next versions.

- The X_NXSetUnpackGeometry request has now a message store.
  This should reduce the overhead to the minimum even in the
  case of dumb agents not checking if the current geometry
  matches the image to be unpacked.

nxcomp-1.3.0-30

- Improved handling of short-circuited replies at X client
  side. Request opcodes are now pushed in the sequence queue
  to determine if a reply is expected. In this case tainting
  of reply is skipped to preserve the sequence ordering of
  any event or error that could have generated by the reply.
  This seems to solve all the problems reported by people
  running a NX session in virtual desktop mode nested in an
  existing session being run in single application mode.

- Modified the cleanup procedure to print the 'Waiting for'
  message in the session log only at the time all X channels
  have been actually shut down. This message can be used by
  the NX server to find out the appropriate time to close
  the session.

- Added the selected session type to the 'Using pack method'
  message printed at startup.

- Added the option to close down the proxy link and perform
  a clean shutdown of the session, re-read the whole session
  configuration or restart the proxy link when a SIGHUP is
  delivered to the proxy process. The default behaviour is
  to close down the session. The new default (the old one was
  to restart the link) is a required feature to let users run
  full sessions using single application mode f.e. in a LTSP
  environment. I noted that when the controlling terminal of
  the X session is closed, a SIGHUP is delivered to the X
  server side proxy (probably it is delivered to all the con-
  nected clients, and, thus for NX, only to the proxy). This
  signal can be used to terminate the whole session.

nxcomp-1.3.0-29

- Changed defaults to disable image masks when running proxy
  in single application mode. The new configuration requires
  changes in NX server and in NX X11 library. Users should
  experience much better image quality when using NX on slow
  links. This comes at the cost of slightly worse compression
  ratios.

nxcomp-1.3.0-28

- Opcode of request was not rewritten by server channel when
  using link LAN. This caused problems with taint of replies.

nxcomp-1.3.0-27

- Modified the split store and the split procedures in client
  channel to always return the client id in the notification
  events. The new field is added to event at byte offset 28
  to preserve compatibility with previous agent releases. The
  modification permits to agent to match the commit of alpha
  channel with the original image, if requests are split by
  proxy.

- Temporarily set the timeout used to poll MIT-SHM completion
  events coming from X server to 0. More testing is required.

- Fixed an inconsistent message generated in statistics due to
  a division by 0.

nxcomp-1.3.0-26

- Modified pending timeout from 1 to 0 milliseconds. This means
  that both channels and proxy are now immediately restarted to
  let them consume all data left in their read buffer.

- When querying the X server for MIT-SHM support, size of name
  in X_QueryExtension request was sent as 32 bits instead of 16.
  This caused request to fail on big endian architectures.

- Modified the MIT-SHM initialization procedure to always send
  all the 3 protocol requests also in the case of early failures.

nxcomp-1.3.0-25

- Implemented handling of the new X_NXSetUnpackAlpha message.
  Performances are very satisfactory. Using most of the current
  GNOME and KDE applications, caching reaches 90% of the total
  messages.

- Modified the persistent cache management routines to handle
  backward compatibility with proxy versions prior of 1.3.0.

- It has been made possible to send both X_NXSetUnpackColormap
  and X_NXSetUnpackAlpha messages with 0 entries to temporarily
  disable use of the colormap or the alpha channel and free the
  resources allocated by the server channel class.

- Added function UnpackAlpha() to Unpack.cpp.

nxcomp-1.3.0-24

- Using WriteBuffer::registerPointer() to track growing of the
  write buffer in handleFastWrite() functions. This problem
  existed even in 1.2.2 but never shown up because we didn't
  have to use the pointer after data had been written to the
  write buffer. Now, instead, we have to post-process the write
  buffer to copy data to the shared segment.

- Optimized memory allocations running with link LAN to save a
  memcpy() any time new data is allocated in the scratch buffer.

- When running with link LAN the scratch buffer is now used only
  when:

  - A further allocation would case growing of the write buffer
    (and, thus, a memcpy() of the previous content).

  - When data to added is bigger than the write threshold.

  In previous versions the scratch buffer was used any time the 
  total amount of data to be written (write buffer + scratch
  buffer) exceeded the scheduled write threshold. This caused
  small writes to be appended even when a single write could
  be  obtained without reallocating the buffer.

- Preliminary support for transporting the alpha channel in a
  separate message in case of 32 bits displays using the RENDER
  extension.

nxcomp-1.3.0-23

- Modified the mask used to open the shared memory segment on
  OS/X to 0777. We have to better investigate why the previous
  0600 mask doesn't work even if the user running the proxy is
  the same user running the X server.

nxcomp-1.3.0-22

- Implemented MIT-SHM support on LAN connections.

- More MIT-SHM bug fixes.

nxcomp-1.3.0-21

- Better use of the shared segment through an improved
  algorithm leveraging the offset field of the X_ShmPutImage
  request. The new algorithm greatly reduces the amount of
  polls the proxy needs to perform to find if the completion
  event has arrived.

- Implemented MIT-SHM support for X_PutImage requests.

- Implemented option shmem=value. Use of this option is anyway
  discouraged. Proxy will allocate the shared memory segment
  based on the size of the in-memory cache set by the user.
  Use of MIT-SHM is disabled when user did set a memory cache
  smaller than 2MB (for example on the embedded client).

- Rewritten post-processing of images in server channel loop.

- Improved error handling to ensure we intercept all MIT-SHM
  X errors before they reach the NX agent.

- Solved a problem that was causing channels to not reflect
  shared memory support flags set in control.

nxcomp-1.3.0-20

- Solved a compatibility problem when mixing proxy versions
  1.2.2 and 1.3.0.

nxcomp-1.3.0-18

- Rewritten interfaces to shared memory initialization in
  client and server channel.

- Server channel checks for the completion event until a
  timeout before reusing the shared memory segment.

- Flush flag was not cleared after the write buffer had been
  flushed in handleWrite() of both client and server channels.
  This could lead to multiple fragmented writes, affecting
  the performances.

- Added -lcygipc to linking on Windows platform.

- Added a check on GCC version to see if -Wnested-externs
  -Wmissing-declarations are valid options.

nxcomp-1.3.0-17

- Implemented initial support for MIT-SHM extension in the
  network path between the X server proxy and the real X
  server. Presently it works only for X_NXPutPackedImages.

- Modified configure.in to compile under FreeBSD.

- Small changes to sources due to FreeBSD support.

nxcomp-1.3.0-16

- Fixed caching of RENDER extension on MacOS/X and Solaris.

- Under Solaris an explicit call to EnableSignal() is needed
  at the end of the signal handler as raising a signal seems
  to reset the previous settings.

- Can't find a way to get bytes queued for write on Solaris as
  both FIONWRITE and TIOCOUTQ don't seem to be available. This
  means that NX server on Solaris is only able to detect con-
  gestions on proxy link at the time a write fails with error
  EAGAIN.

- Starting from this version, render extension messages are not
  automatically discarded from cache when running agent based X
  sessions. This is in preparation of render support introduced
  in this release.

nxcomp-1.3.0-15

- Changed default to force writes if X channels exceed buffer
  limits. This change was suggested by benchmarks performed on
  Win32.

- Wrapped IO on cache files in functions performing better error
  checking.

- General cleanup in handling of socket options for MacOS/X and
  Solaris.

nxcomp-1.3.0-14

- Corrupted persistent caches were not deleted in case loading
  of any of the message stores failed. To run further sessions
  on the same host, user had to delete the cache file manually.

- Improved error handling in JPEG decompression. Now connection
  is reset in case of failure.

- Before performing JPEG or PNG decompression, image is better
  checked to verify if loading from disk failed.

- Improved error handling in case of failure loading persistent
  cache from disk. On MacOS/X istream -> fail() doesn't seem to
  work properly. This needs further investigation.

- The default installation path of nxclient is searched under
  MacOS/X at the time nxclient is invoked in dialog mode.

nxcomp-1.3.0-13

- Fixed a (further) compilation problem under Solaris. Now static
  libraries are first searched under /usr/sfw/lib (in case Sun
  would decide to include them in future releases).

nxcomp-1.3.0-12

- Fixed parsing of command line when passing option -V.

- Correctly detected ENOPROTOOPT when setting TCP_NODELAY socket
  option on MacOS/X and Solaris.

nxcomp-1.3.0-11

- Given option in configure to specify what needs to be built
  statically:

  --with-static-png     enable static linking of PNG library
  --with-static-jpeg    enable static linking of JPEG library
  --with-static-z       enable static linking of Z library

nxcomp-1.3.0-10

- Fixed a problem in saving of persistent cache on big-endian
  machines.

nxcomp-1.3.0-9

- Testing with different settings to check if it's possible to
  increase the performances under Windows.

- Solved a problem in parsing of options that prevented proxy
  to connect to a remote session running at port offset 0.

- Fixed two warnings compiling on Solaris.

- Changed configure.in to first check for nx-X11 includes
  and libraries. Added "/usr/openwin/bin/makedepend" to path
  searched for the executable.

nxcomp-1.3.0-8

- Small cleanup in configure.in and files modified by Gregorz
  Kryza to add support for Solaris.

- A new configure script has been generated using autoconf-2.57-3.

nxcomp-1.3.0-7

- Added support for detection of Solaris in configure script.
  Now Makefile.in uses ranlib instead of ar.

- Small changes in source and header files to support Solaris.

nxcomp-1.3.0-4

- Corrected a bug that could cause priority on proxy and channels 
  to be not taken in account at the time proxy tries to determine 
  if it's time to flush the proxy link.

- Better implementation of abort split notification by X server
  proxy to its remote peer. The new implementation doesn't
  need to set a timeout and permits notifications to be received
  earlier.

- Improved support for 'tainting' XSync() messages coming from 
  X clients in single application mode. Now a X_GetInputFocus
  is sent to the real X server any n such messages received by
  proxy. 

- Included support for 15 bpp displays. It seems that handling
  them as 16 bpp it's OK.