Reimplement xinerama via randr in nxagent (not libNX_Xinerama). (Fixes ArcticaProject/nx-libs#23).

 No more xinerama faking, just use existing xrandr extension and initalize
 it properly. Xinerama then works automatically.

 Fixes ArcticaProject/nx-libs#23

5 files changed, 452 insertions, 71 deletions

diff --git a/nx-X11/programs/Xserver/hw/nxagent/Events.c b/nx-X11/programs/Xserver/hw/nxagent/Events.c
index 9f7d6280f..03b14f0dc 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Events.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Events.c
@@ -568,6 +568,10 @@ void nxagentSwitchResizeMode(ScreenPtr pScreen)
 {
   XSizeHints sizeHints;
 
+  #ifdef DEBUG
+  fprintf(stderr, "nxagentSwitchResizeMode called.\n");
+  #endif
+
   int desktopResize = nxagentOption(DesktopResize);
 
   nxagentChangeOption(DesktopResize, !desktopResize);
@@ -3366,7 +3370,9 @@ int nxagentHandleConfigureNotify(XEvent* X)
         if (nxagentOption(DesktopResize) == 1)
         {
           if (nxagentOption(Width) != X -> xconfigure.width ||
-                nxagentOption(Height) != X -> xconfigure.height)
+                nxagentOption(Height) != X -> xconfigure.height ||
+                nxagentOption(X) != X -> xconfigure.x ||
+                nxagentOption(Y) != X -> xconfigure.y)
           {
             Bool newEvents = False;
 
@@ -3423,11 +3429,16 @@ int nxagentHandleConfigureNotify(XEvent* X)
 
         nxagentMoveViewport(pScreen, 0, 0);
 
+        /* if in shadowing mode or if neither size nor position have
+           changed we do not need to adjust RandR */
+        /* FIXME: Comment makes no sense */
         if (nxagentOption(Shadow) == 1 ||
                 (nxagentOption(Width) == nxagentOption(RootWidth) &&
-                    nxagentOption(Height) == nxagentOption(RootHeight)))
+		 nxagentOption(Height) == nxagentOption(RootHeight) &&
+		 nxagentOption(X) == nxagentOption(RootX) &&
+		 nxagentOption(Y) == nxagentOption(RootY)))
         {
-          doRandR = 0;
+          doRandR = False;
         }
 
         nxagentChangeOption(Width, X -> xconfigure.width);
@@ -3466,12 +3477,31 @@ int nxagentHandleConfigureNotify(XEvent* X)
           #endif
 
           nxagentChangeScreenConfig(0, nxagentOption(Width),
-                                        nxagentOption(Height), 0, 0);
+                                       nxagentOption(Height), 0, 0);
         }
       }
 
       return 1;
     }
+    else
+    {
+      if (X -> xconfigure.window == DefaultRootWindow(nxagentDisplay))
+      {
+        #ifdef TEST
+        fprintf(stderr, "nxagentHandleConfigureNotify: remote root window has changed: %d,%d %dx%d\n", X -> xconfigure.x, X -> xconfigure.y, X -> xconfigure.width, X -> xconfigure.height);
+        #endif
+
+        nxagentChangeOption(RootX, X -> xconfigure.x);
+        nxagentChangeOption(RootY, X -> xconfigure.y);
+        nxagentChangeOption(RootWidth, X -> xconfigure.width);
+        nxagentChangeOption(RootHeight, X -> xconfigure.height);
+
+        nxagentChangeScreenConfig(0, nxagentOption(Width),
+                                     nxagentOption(Height), 0, 0);
+
+        return 1;
+      }
+    }
   }
 
   return 0;
@@ -4416,6 +4446,10 @@ int nxagentHandleRRScreenChangeNotify(XEvent *X)
 {
   XRRScreenChangeNotifyEvent *Xr;
 
+  #ifdef DEBUG
+  fprintf(stderr, "nxagentHandleRRScreenChangeNotify called.\n");
+  #endif
+
   Xr = (XRRScreenChangeNotifyEvent *) X;
 
   nxagentResizeScreen(screenInfo.screens[DefaultScreen(nxagentDisplay)], Xr -> width, Xr -> height,
@@ -4504,6 +4538,10 @@ int nxagentWaitEvents(Display *dpy, struct timeval *tm)
 {
   XEvent ev;
 
+  #ifdef DEBUG
+  fprintf(stderr, "nxagentWaitEvents called.\n");
+  #endif
+
   NXFlushDisplay(dpy, NXFlushLink);
 
   /*
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Extensions.c b/nx-X11/programs/Xserver/hw/nxagent/Extensions.c
index 6dce644ae..103eaa92c 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Extensions.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Extensions.c
@@ -35,6 +35,11 @@ static int nxagentRandRScreenSetSize(ScreenPtr pScreen, CARD16 width,
 
 static int nxagentRandRInitSizes(ScreenPtr pScreen);
 
+static Bool nxagentRandRCrtcSet (ScreenPtr pScreen, RRCrtcPtr crtc,
+				 RRModePtr mode, int x, int y,
+				 Rotation rotation, int numOutputs,
+				 RROutputPtr *outputs);
+
 #ifdef __DARWIN__
 
 void DarwinHandleGUI(int argc, char *argv[])
@@ -83,6 +88,8 @@ void nxagentInitRandRExtension(ScreenPtr pScreen)
     fprintf(stderr, "Warning: Failed to initialize the RandR extension.\n");
   }
 
+
+  /* FIXME: do we need this at all with the new rand/xinerama stuff? */
   nxagentRandRInitSizes(pScreen);
 
   /*
@@ -97,6 +104,7 @@ void nxagentInitRandRExtension(ScreenPtr pScreen)
 
   #if RANDR_12_INTERFACE
   pRandRScrPriv -> rrScreenSetSize = nxagentRandRScreenSetSize;
+  pRandRScrPriv -> rrCrtcSet = nxagentRandRCrtcSet;
   #endif
 
   #if RANDR_10_INTERFACE
@@ -104,6 +112,34 @@ void nxagentInitRandRExtension(ScreenPtr pScreen)
   #endif
 }
 
+void
+RRResetProc (ExtensionEntry *extEntry)
+{
+  fprintf(stderr, "RANDR going down - NX version\n");
+}
+
+
+
+#if RANDR_12_INTERFACE
+/*
+ * Request that the Crtc be reconfigured
+ */
+
+static Bool
+nxagentRandRCrtcSet (ScreenPtr   pScreen,
+		     RRCrtcPtr   crtc,
+		     RRModePtr   mode,
+		     int         x,
+		     int         y,
+		     Rotation    rotation,
+		     int         numOutputs,
+		     RROutputPtr *outputs)
+{
+  return RRCrtcNotify(crtc, mode, x, y, rotation, numOutputs, outputs);
+}
+#endif
+
+
 int nxagentRandRGetInfo(ScreenPtr pScreen, Rotation *pRotations)
 {
   /*
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Options.c b/nx-X11/programs/Xserver/hw/nxagent/Options.c
index 7eac3d8a2..dbe200273 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Options.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Options.c
@@ -154,6 +154,8 @@ void nxagentInitOptions()
   nxagentOptions.CopyBufferSize = COPY_UNLIMITED;
 
   nxagentOptions.ImageRateLimit = 0;
+
+  nxagentOptions.Xinerama = 0;
 }
 
 /*
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Options.h b/nx-X11/programs/Xserver/hw/nxagent/Options.h
index 0e4869926..5bf1597d5 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Options.h
+++ b/nx-X11/programs/Xserver/hw/nxagent/Options.h
@@ -388,6 +388,17 @@ typedef struct _AgentOptions
 
   int NoRootlessExit;
 
+ /*
+  * Store if the user wants Xinerama. There's a variable called
+  * noPanoramiXExtension in os/utils.c but we cannot rely on that
+  * because RandR and Panoramix change its value when trying to
+  * initialize. So we use this variable to save the user preference
+  * provided by the -/+xinerama parameter before initalizing those
+  * extensions.
+  */
+
+  int Xinerama;
+
 } AgentOptionsRec;
 
 typedef AgentOptionsRec *AgentOptionsPtr;
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Screen.c b/nx-X11/programs/Xserver/hw/nxagent/Screen.c
index 2f70334d4..ec34eddb6 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Screen.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Screen.c
@@ -133,14 +133,6 @@ extern Pixmap nxagentIconPixmap;
 extern Pixmap nxagentIconShape;
 extern Bool useXpmIcon;
 
-/*
- * From randr/randr.c.
- */
-
-extern Bool RRGetInfo(ScreenPtr pScreen);
-extern void RRSendConfigNotify(ScreenPtr pScreen);
-extern void RREditConnectionInfo(ScreenPtr pScreen);
-
 Window nxagentDefaultWindows[MAXSCREENS];
 Window nxagentInputWindows[MAXSCREENS];
 Window nxagentScreenSaverWindows[MAXSCREENS];
@@ -323,7 +315,7 @@ void nxagentMaximizeToFullScreen(ScreenPtr pScreen)
     XUnmapWindow(nxagentDisplay, nxagentIconWindow);
 */
 /*
-FIXME: We'll chech for ReparentNotify and LeaveNotify events after XReparentWindow()
+FIXME: We'll check for ReparentNotify and LeaveNotify events after XReparentWindow()
        in order to avoid the session window is iconified.
        We could avoid the sesssion window is iconified when a LeaveNotify event is received,
        so this check would be unnecessary.
@@ -1121,6 +1113,9 @@ Bool nxagentOpenScreen(int index, ScreenPtr pScreen,
   nxagentChangeOption(ViewportXSpan, nxagentOption(Width) - nxagentOption(RootWidth));
   nxagentChangeOption(ViewportYSpan, nxagentOption(Height) - nxagentOption(RootHeight));
 
+  /* store the user's preference provided via cmdline */
+  nxagentOption(Xinerama) = !noPanoramiXExtension;
+
   if (nxagentReconnectTrap == 0)
   {
     if (nxagentOption(Persistent))
@@ -2039,6 +2034,9 @@ N/A
 
   nxagentCompositeExtensionInit();
 
+  /* We use this to get informed about RandR changes on the real display.
+     FIXME: It would probably be better to use an RRScreenChangeNotifyEvent here. */
+  XSelectInput(nxagentDisplay, DefaultRootWindow(nxagentDisplay), StructureNotifyMask);
 
   #ifdef NXAGENT_TIMESTAMP
 
@@ -2075,6 +2073,10 @@ Bool nxagentCloseScreen(int index, ScreenPtr pScreen)
 {
   int i;
 
+  #ifdef DEBUG
+  fprintf(stderr, "running nxagentCloseScreen()\n");
+  #endif
+
   for (i = 0; i < pScreen->numDepths; i++)
   {
     xfree(pScreen->allowedDepths[i].vids);
@@ -3589,21 +3591,61 @@ Bool nxagentReconnectScreen(void *p0)
   return True;  
 }
 
-RRModePtr    nxagentRRCustomMode = NULL;
+/* FIXME: there must be such macros somewhere already...*/
+#define MAX(a,b) ((a) > (b)) ? (a) : (b);
+#define MIN(a,b) ((a) < (b)) ? (a) : (b);
+
+/* intersect two rectangles */
+Bool intersect(int ax1, int ay1, unsigned int aw, unsigned int ah,
+	       int bx1, int by1, unsigned int bw, unsigned int bh,
+	       int *x, int *y, unsigned int *w, unsigned int *h)
+{
+    int tx1, ty1, tx2, ty2, ix, iy;
+    unsigned int iw, ih;
+
+    int ax2 = ax1 + aw;
+    int ay2 = ay1 + ah;
+    int bx2 = bx1 + bw;
+    int by2 = by1 + bh;
+
+    /* thanks to http://silentmatt.com/rectangle-intersection */
+
+    /* check if there's any intersection at all */
+    if (ax2 < bx1 || bx2 < ax1 || ay2 < by1 || by2 < ay1) {
+        return FALSE;
+    }
+
+    tx1 = MAX(ax1, bx1);
+    ty1 = MAX(ay1, by1);
+    tx2 = MIN(ax2, bx2);
+    ty2 = MIN(ay2, by2);
+
+    ix = tx1 - ax1;
+    iy = ty1 - ay1;
+    iw = tx2 - tx1;
+    ih = ty2 - ty1;
+
+    /* check if the resulting rectangle is feasible */
+    if (iw <= 0 || ih <= 0) {
+        return FALSE;
+    }
+    *x = ix;
+    *y = iy;
+    *w = iw;
+    *h = ih;
+    return TRUE;
+}
 
 int nxagentChangeScreenConfig(int screen, int width, int height, int mmWidth, int mmHeight)
 {
   ScreenPtr    pScreen;
-  rrScrPrivPtr pScrPriv;
-  RROutputPtr  output;
-  RRCrtcPtr    crtc;
-  RRModePtr    mode;
-  xRRModeInfo  modeInfo;
-  char         name[100];
-  int          r, c, m;
-  int          refresh = 60;
-  int          doNotify = 1;
+  /* FIXME: when is this needed? */
+  int          doNotify = TRUE;
+  int          r;
 
+  #ifdef TEST
+  fprintf(stderr, "nxagentChangeScreenConfig: WindowTable[%d] is %p\n", screen, WindowTable[screen]);
+  #endif
   if (WindowTable[screen] == NULL)
   {
     return 0;
@@ -3611,16 +3653,16 @@ int nxagentChangeScreenConfig(int screen, int width, int height, int mmWidth, in
 
   UpdateCurrentTime();
 
-  if (nxagentGrabServerInfo.grabstate == SERVER_GRABBED)
+  if (nxagentGrabServerInfo.grabstate == SERVER_GRABBED && nxagentGrabServerInfo.client != NULL)
   {
     /*
      * If any client grabbed the server it won't expect that screen
      * configuration changes until it releases the grab. That could
-     * get an X error because available modes are chanded meanwhile.
+     * get an X error because available modes are changed meanwhile.
      */
 
     #ifdef TEST
-    fprintf(stderr, "nxagentChangeScreenConfig: Cancel with grabbed server.\n");
+    fprintf(stderr, "nxagentChangeScreenConfig: Cancel with grabbed server (grab held by %p).\n", nxagentGrabServerInfo.client);
     #endif
 
     return 0;
@@ -3636,76 +3678,328 @@ int nxagentChangeScreenConfig(int screen, int width, int height, int mmWidth, in
 
   if (r != 0)
   {
-    pScrPriv = rrGetScrPriv(pScreen);
+    nxagentAdjustRandRXinerama(pScreen);
+  }
+
+  if (doNotify)
+  {
+    RRScreenSizeNotify(pScreen);
+  }
+
+#ifdef DEBUG
+  fprintf(stderr, "nxagentChangeScreenConfig: Geometry: %d,%d %dx%d\n", nxagentOption(X), nxagentOption(Y),nxagentOption(Width),nxagentOption(Height));
+  fprintf(stderr, "nxagentChangeScreenConfig: return %d\n", r);
+#endif
+
+  return r;
+}
 
-    if (pScrPriv)
+int nxagentAdjustRandRXinerama(ScreenPtr pScreen)
+{
+  rrScrPrivPtr pScrPriv;
+  RROutputPtr  output;
+  xRRModeInfo  modeInfo;
+  char         name[100];
+  int          refresh = 60;
+  int          width = nxagentOption(Width);
+  int          height = nxagentOption(Height);
+
+  pScrPriv = rrGetScrPriv(pScreen);
+
+  if (pScrPriv)
+  {
+    int i, j;
+    int number = 0;
+
+    XineramaScreenInfo *screeninfo = NULL;
+
+    if (nxagentOption(Xinerama)) {
+      screeninfo = XineramaQueryScreens(nxagentDisplay, &number);
+#ifdef DEBUG
+      if (number) {
+        fprintf(stderr, "nxagentAdjustRandRXinerama: XineramaQueryScreens() returned %d screens\n", number);
+      }
+      else
+      {
+        fprintf(stderr, "nxagentAdjustRandRXinerama: XineramaQueryScreens() failed - continuing without xinerama\n");
+      }
+    }
+    else
+    {
+      fprintf(stderr, "nxagentAdjustRandRXinerama: Xinerama is disabled\n");
+#endif
+    }
+
+    /*
+     * if there's no xinerama on the real server or xinerama is
+     * disabled in nxagent we only report one big screen. Clients
+     * still see xinerama enabled but it will report only one (big)
+     * screen. This is consistent with the way rrxinerama always
+     * behaved. The single PanoramiX/Xinerama extension however
+     * disables xinerama if only one screen exists.
+     */
+    if (number == 0) {
+      #ifdef DEBUG
+      fprintf(stderr, "nxagentAdjustRandRXinerama: faking xinerama\n" );
+      #endif
+      number = 1;
+
+      if (screeninfo) {
+	xfree(screeninfo);
+      }
+      if (!(screeninfo = xalloc(sizeof(XineramaScreenInfo)))) {
+	return FALSE;
+      }
+
+      /* fake a xinerama screeninfo that covers the whole screen */
+      screeninfo->x_org = nxagentOption(X);
+      screeninfo->y_org = nxagentOption(Y);
+      screeninfo->width = nxagentOption(Width);
+      screeninfo->height = nxagentOption(Height);
+    }
+
+#ifdef DEBUG
+    fprintf(stderr, "nxagentAdjustRandRXinerama: numCrtcs = %d, numOutputs = %d\n", pScrPriv->numCrtcs, pScrPriv->numOutputs);
     {
-      output = RRFirstOutput(pScreen);
+      Bool rrgetinfo;
 
-      if (output && output -> crtc)
+      /*
+       * Convert old RANDR 1.0 data (if any) to current structure. This
+       * is needed once at the first run of this function. If we don't
+       * do this here it will be done implicitely later and add mode(s) to
+       * our crtc(s)!
+       */
+      rrgetinfo = RRGetInfo(pScreen);
+
+      fprintf(stderr, "nxagentAdjustRandRXinerama: RRGetInfo returned %d\n", rrgetinfo);
+    }
+#else
+    /* we are not interested in the return code */
+    RRGetInfo(pScreen);
+#endif
+
+    #ifdef DEBUG
+    fprintf(stderr, "nxagentAdjustRandRXinerama: numCrtcs = %d, numOutputs = %d\n", pScrPriv->numCrtcs, pScrPriv->numOutputs);
+    #endif
+
+    /* adjust the number of CRTCs to match the number of reported
+       xinerama screens on the real server */
+    while (number != pScrPriv->numCrtcs) {
+      if (number < pScrPriv->numCrtcs) {
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: destroying crtc\n");
+        #endif
+        RRCrtcDestroy(pScrPriv->crtcs[pScrPriv->numCrtcs - 1]);
+      }
+      else
       {
-        crtc = output -> crtc;
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: adding crtc\n");
+        #endif
+        RRCrtcCreate(pScreen, NULL);
+      }
+    }
 
-        for (c = 0; c < pScrPriv -> numCrtcs; c++)
-        {
-          RRCrtcSet(pScrPriv -> crtcs[c], NULL, 0, 0, RR_Rotate_0, 0, NULL);
+    #ifdef DEBUG
+    fprintf(stderr, "nxagentAdjustRandRXinerama: numCrtcs = %d, numOutputs = %d\n", pScrPriv->numCrtcs, pScrPriv->numOutputs);
+    #endif
+
+    /* set gamma. Currently the only reason for doing this is
+       preventing the xrandr command from complaining about missing
+       gamma. */
+    for (i = 0; i < pScrPriv->numCrtcs; i++) {
+      if (pScrPriv->crtcs[i]->gammaSize == 0) {
+	CARD16 gamma = 0;
+	RRCrtcGammaSetSize(pScrPriv->crtcs[i], 1);
+	RRCrtcGammaSet(pScrPriv->crtcs[i], &gamma, &gamma, &gamma);
+	RRCrtcGammaNotify(pScrPriv->crtcs[i]);
+      }
+    }
+
+    /* delete superfluous non-NX outputs */
+    for (i = pScrPriv->numOutputs - 1; i >= 0; i--) {
+      if (strncmp(pScrPriv->outputs[i]->name, "NX", 2)) {
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: destroying output %s\n", pScrPriv->outputs[i]->name);
+        #endif
+        RROutputDestroy(pScrPriv->outputs[i]);
+      }
+    }
+
+    /* at this stage only NX outputs are left - we delete the superfluous ones */
+    for (i = pScrPriv->numOutputs - 1; i >= number; i--) {
+      #ifdef DEBUG
+      fprintf(stderr, "nxagentAdjustRandRXinerama: destroying output %s\n", pScrPriv->outputs[i]->name);
+      #endif
+      RROutputDestroy(pScrPriv->outputs[i]);
+    }
+
+    /* add and init outputs */
+    for (i = 0; i < number; i++) {
+      if (i >= pScrPriv->numOutputs) {
+        sprintf(name, "NX%d", i+1);
+        output = RROutputCreate(pScreen, name, strlen(name), NULL);
+	/* will be done later
+	RROutputSetConnection(output, RR_Disconnected); 
+	*/
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: created new output %s\n", name);
+        #endif
+      }
+      else
+      {
+        output = pScrPriv->outputs[i];
+      }
+      #ifdef DEBUG
+      fprintf(stderr, "nxagentAdjustRandRXinerama: adjusting output %s\n",  pScrPriv->outputs[i]->name);
+      #endif
+      RROutputSetCrtcs(output, &(pScrPriv->crtcs[i]), 1);
+      /* FIXME: Isn't there a function for setting this? */
+      output->crtc = pScrPriv->crtcs[i];
+      /* FIXME: get SubPixelOrder from real X server */
+      RROutputSetSubpixelOrder(output, SubPixelUnknown);
+      /* FIXME: What is the correct physical size here? */
+      RROutputSetPhysicalSize(output, 0, 0);
+    }
+
+    for (i = 0; i < pScrPriv->numOutputs; i++ ) {
+      Bool disable_output = FALSE;
+      RRModePtr mymode, prevmode;
+      int new_x, new_y;
+      unsigned int new_w, new_h;
+
+      /* if there's no intersection disconnect the output */
+      disable_output = !intersect(nxagentOption(X), nxagentOption(Y),
+                                  width, height,
+                                  screeninfo[i].x_org, screeninfo[i].y_org,
+                                  screeninfo[i].width, screeninfo[i].height,
+                                  &new_x, &new_y, &new_w, &new_h);
+
+      RROutputSetCrtcs(pScrPriv->outputs[i], &(pScrPriv->crtcs[i]), 1);
+
+      /* save previous mode */
+      prevmode = pScrPriv->crtcs[i]->mode;
+
+      if (disable_output) {
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: output %d: no (valid) intersection - disconnecting\n", i);
+        #endif
+        RROutputSetConnection(pScrPriv->outputs[i], RR_Disconnected);
+
+        /*
+         * Tests revealed that some window managers (e.g. LXDE) also
+         * take disconnected outputs into account when calculating
+         * stuff like wallpaper tile size and maximum window
+         * size. This is problematic when the disconnected output is
+         * smaller than any of the connected ones. Solution: unset
+         * the mode of the output's crtc.  This also leads to
+         * xinerama not showing the disconnected head anymore.
+         */
+        RRCrtcSet(pScrPriv->crtcs[i], NULL, 0, 0, RR_Rotate_0, 1, &(pScrPriv->outputs[i]));
+        RROutputSetModes(pScrPriv->outputs[i], NULL, 0, 0);
+        if(prevmode) {
+          if(prevmode->refcnt == 1)
+            FreeResource(prevmode->mode.id, 0);
         }
+      }
+      else
+      {
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: crtc %d: intersection is x=%d, y=%d, width=%d, height=%d'\n", i, new_x, new_y, new_w, new_h);
+        #endif
+        RROutputSetConnection(pScrPriv->outputs[i], RR_Connected);
 
         memset(&modeInfo, '\0', sizeof(modeInfo));
-        sprintf(name, "%dx%d", width, height);
-
-        modeInfo.width  = width;
-        modeInfo.height = height;
-        modeInfo.hTotal = width;
-        modeInfo.vTotal = height;
-        modeInfo.dotClock = ((CARD32) width * (CARD32) height *
-                                (CARD32) refresh);
+        /* avoid collisions with pre-existing default modes by using a
+           separate namespace. If we'd simply use XxY we could not
+           distinguish between pre-existing modes which should stay
+           and our own modes that should be removed after use. */
+        /*sprintf(name, "nx%d", i+1);*/
+        /*sprintf(name, "%dx%d", new_w, new_h);*/
+        sprintf(name, "nx_%dx%d", new_w, new_h);
+
+        modeInfo.width  = new_w;
+        modeInfo.height = new_h;
+        modeInfo.hTotal = new_w;
+        modeInfo.vTotal = new_h;
+        modeInfo.dotClock = ((CARD32) new_w * (CARD32) new_h * (CARD32) refresh);
         modeInfo.nameLength = strlen(name);
 
-        if (nxagentRRCustomMode != NULL)
+        mymode = RRModeGet(&modeInfo, name);
+
+#ifdef DEBUG
+        if (mymode) {
+          fprintf(stderr, "nxagentAdjustRandRXinerama: mode %s (%p) created/received, refcnt=%d\n", name, mymode, mymode->refcnt);
+        }
+        else
         {
-          RROutputDeleteUserMode(output, nxagentRRCustomMode);
-          FreeResource(nxagentRRCustomMode -> mode.id, 0);
+          fprintf(stderr, "nxagentAdjustRandRXinerama: mode %s creation failed!\n", name);
+        }
+#endif
 
-          if (crtc != NULL && crtc -> mode == nxagentRRCustomMode)
+        if (prevmode) {
+          if (mymode == prevmode)
           {
-            RRCrtcSet(crtc, NULL, 0, 0, RR_Rotate_0, 0, NULL);
+            /* if they are the same RRModeGet() has increased the
+               refcnt by 1. We decrease it again by calling only
+               RRModeDestroy() and forget about prevmode */
+          } else {
+            RROutputSetModes(pScrPriv->outputs[i], &mymode, 1, 0);
+            RRCrtcSet(pScrPriv->crtcs[i], mymode, new_x, new_y, RR_Rotate_0, 1, &(pScrPriv->outputs[i]));
           }
-
-          #ifdef TEST
-          fprintf(stderr, "nxagentChangeScreenConfig: "
-                      "Going to destroy mode %p with refcnt %d.\n",
-                          nxagentRRCustomMode, nxagentRRCustomMode->refcnt);
-          #endif
-
-          RRModeDestroy(nxagentRRCustomMode);
+          if(prevmode->refcnt == 1)
+            FreeResource(prevmode->mode.id, 0);
+        }
+        else
+        {
+          /* we do not have a previous mode, so there's no need to handle it here */
+          RROutputSetModes(pScrPriv->outputs[i], &mymode, 1, 0);
+          RRCrtcSet(pScrPriv->crtcs[i], mymode, new_x, new_y, RR_Rotate_0, 1, &(pScrPriv->outputs[i]));
         }
 
-        nxagentRRCustomMode = RRModeGet(&modeInfo, name);
-
-        RROutputAddUserMode(output, nxagentRRCustomMode);
+        #ifdef DEBUG
+        fprintf(stderr, "nxagentAdjustRandRXinerama: mode %s (%p) added to output and crtc %d\n", name, mymode, i);
+        #endif
+      } /* if disable_output */
 
-        RRCrtcSet(crtc, nxagentRRCustomMode, 0, 0, RR_Rotate_0, 1, &output);
+      RROutputChanged(pScrPriv->outputs[i], TRUE);
+      RRCrtcChanged(pScrPriv->crtcs[i], TRUE);
+    }
 
-        RROutputChanged(output, 1);
+    /* release allocated memory */
+    if (screeninfo) {
+      xfree(screeninfo);
+      screeninfo = NULL;
+    }
 
-        doNotify = 0;
+#ifdef DEBUG
+    for (i = 0; i < pScrPriv->numCrtcs; i++) {
+      RRModePtr mode = pScrPriv->crtcs[i]->mode;
+      if (mode) {
+        fprintf(stderr, "nxagentAdjustRandRXinerama: crtc %d has mode %s and %d outputs\n", i, pScrPriv->crtcs[i]->mode->name, pScrPriv->crtcs[i]->numOutputs);
+      }
+      else
+      {
+        fprintf(stderr, "nxagentAdjustRandRXinerama: crtc %d has no mode and %d outputs\n", i, pScrPriv->crtcs[i]->numOutputs);
       }
 
-      pScrPriv -> lastSetTime = currentTime;
-
-      pScrPriv->changed = 1;
-      pScrPriv->configChanged = 1;
+      fprintf(stderr, "nxagentAdjustRandRXinerama: output[%d]->crtc=%p\n", i, pScrPriv->outputs[i]->crtc);
     }
+#endif
 
-    if (doNotify
-)
-    {
-      RRScreenSizeNotify(pScreen);
-    }
+    pScrPriv -> lastSetTime = currentTime;
+
+    pScrPriv->changed = TRUE;
+    pScrPriv->configChanged = TRUE;
   }
 
-  return r;
+  /* FIXME: adjust maximum screen size according to remote randr/xinerama setup */
+
+  #ifdef DEBUG
+  fprintf(stderr, "nxagentAdjustRandRXinerama: Min %dx%d, Max %dx%d \n", pScrPriv->minWidth,pScrPriv->minHeight,pScrPriv->maxWidth,pScrPriv->maxHeight);
+  #endif
+
+  return TRUE;
 }
 
 void nxagentSaveAreas(PixmapPtr pPixmap, RegionPtr prgnSave, int xorg, int yorg, WindowPtr pWin)