Clipboard.c: translate internal to external atom

serverClientCutProperty is the external equivalent of the internal
clientCutProperty. We need it on the server side, too, because we use
the property on the serverWindow on the real X server. We could
(mis)use serverCutProperty here but this might introduce race
conditions when both sides request selections simultaneously.

3 files changed, 22 insertions, 5 deletions

diff --git a/nx-X11/programs/Xserver/hw/nxagent/Atoms.c b/nx-X11/programs/Xserver/hw/nxagent/Atoms.c
index 1c48df61c..d9d203faa 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Atoms.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Atoms.c
@@ -90,6 +90,7 @@ static char *nxagentAtomNames[NXAGENT_NUMBER_OF_ATOMS + 1] =
   "UTF8_STRING",                 /* 12 */
   "_NET_WM_STATE",               /* 13 */
   "_NET_WM_STATE_FULLSCREEN",    /* 14 */
+  "NX_CUT_BUFFER_CLIENT",        /* 15 */
   NULL,
   NULL
 };
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Atoms.h b/nx-X11/programs/Xserver/hw/nxagent/Atoms.h
index 08eb1cfff..cbbb7bd1d 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Atoms.h
+++ b/nx-X11/programs/Xserver/hw/nxagent/Atoms.h
@@ -30,7 +30,7 @@
 #include "../../include/window.h"
 #include "screenint.h"
 
-#define NXAGENT_NUMBER_OF_ATOMS  16
+#define NXAGENT_NUMBER_OF_ATOMS  17
 
 extern Atom nxagentAtoms[NXAGENT_NUMBER_OF_ATOMS];
 
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Clipboard.c b/nx-X11/programs/Xserver/hw/nxagent/Clipboard.c
index 8255612ac..5d6c7cd7f 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Clipboard.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Clipboard.c
@@ -129,6 +129,7 @@ static Atom serverTARGETS;
 static Atom serverTIMESTAMP;
 static Atom serverTEXT;
 static Atom serverUTF8_STRING;
+static Atom serverClientCutProperty;
 static Atom clientTARGETS;
 static Atom clientTEXT;
 static Atom clientCOMPOUND_TEXT;
@@ -328,6 +329,8 @@ void nxagentPrintClipboardStat(char *header)
   fprintf(stderr, "  serverUTF8_STRING                      [% 4d][%s]\n", serverUTF8_STRING, s);
   SAFE_XFree(s); s = XGetAtomName(nxagentDisplay, serverCutProperty);
   fprintf(stderr, "  serverCutProperty                      [% 4d][%s]\n", serverCutProperty, s);
+  SAFE_XFree(s); s = XGetAtomName(nxagentDisplay, serverClientCutProperty);
+  fprintf(stderr, "  serverClientCutProperty                [% 4d][%s]\n", serverClientCutProperty, s);
 
   SAFE_XFree(s); s = XGetAtomName(nxagentDisplay, serverTIMESTAMP);
   fprintf(stderr, "  serverTIMESTAMP                        [% 4d][%s]\n", serverTIMESTAMP, s);
@@ -1127,7 +1130,7 @@ void nxagentNotifySelection(XEvent *X)
     {
       if ((lastSelectionOwner[i].client != NULL) &&
              (lastSelectionOwner[i].windowPtr != NULL) &&
-                 (X->xselection.property == clientCutProperty))
+                 (X->xselection.property == serverClientCutProperty))
       {
         Atom            atomReturnType;
         int             resultFormat;
@@ -1624,19 +1627,30 @@ int nxagentSendNotify(xEvent *event)
 
     /*
      * Setup selection notify event to real server.
+     *
+     * .property must be a server-side Atom. As this property is only
+     * set on our serverWindow and normally there are no other
+     * properties except serverCutProperty, the only thing we need to
+     * ensure is that the internal Atom clientCutProperty must differ
+     * from the server-side serverCutProperty Atom. The actual name is
+     * not important. To be clean here we use a seperate
+     * serverClientCutProperty.
      */
 
     XSelectionEvent eventSelection = {
       .requestor = serverWindow,
       .selection = event->u.selectionNotify.selection,
       .target    = event->u.selectionNotify.target,
-      .property  = event->u.selectionNotify.property,
+      .property  = serverClientCutProperty,
       .time      = CurrentTime,
     };
 
     /*
-     * On real server, the right CLIPBOARD atom is
-     * XInternAtom(nxagentDisplay, "CLIPBOARD", 1).
+     * On the real server, the right CLIPBOARD atom is
+     * XInternAtom(nxagentDisplay, "CLIPBOARD", 1), which is stored in
+     * lastSelectionOwner[nxagentClipboardSelection].selection. For
+     * PRIMARY there's nothing to map because that is identical on all
+     * X servers (defined in Xatom.h).
      */
 
     if (event->u.selectionNotify.selection == MakeAtom("CLIPBOARD", 9, 0))
@@ -1728,6 +1742,8 @@ int nxagentInitClipboard(WindowPtr pWin)
   serverTARGETS = nxagentAtoms[6];  /* TARGETS */
   serverTEXT = nxagentAtoms[7];  /* TEXT */
   serverUTF8_STRING = nxagentAtoms[12]; /* UTF8_STRING */
+  /* see nxagentSendNotify for an explanation */
+  serverClientCutProperty = nxagentAtoms[15]; /* NX_CUT_BUFFER_CLIENT */
 
   if (serverCutProperty == None)
   {