xserver git update 15/5/2010

1 files changed, 347 insertions, 347 deletions

diff --git a/xorg-server/hw/dmx/dmxprop.c b/xorg-server/hw/dmx/dmxprop.c
index 376313d8d..95efcb0e0 100644
--- a/xorg-server/hw/dmx/dmxprop.c
+++ b/xorg-server/hw/dmx/dmxprop.c
@@ -1,347 +1,347 @@
-/*
- * Copyright 2002-2003 Red Hat Inc., Durham, North Carolina.
- *
- * All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation on the rights to use, copy, modify, merge,
- * publish, distribute, sublicense, and/or sell copies of the Software,
- * and to permit persons to whom the Software is furnished to do so,
- * subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial
- * portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NON-INFRINGEMENT.  IN NO EVENT SHALL RED HAT AND/OR THEIR SUPPLIERS
- * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-/*
- * Authors:
- *   Rickard E. (Rik) Faith <faith@redhat.com>
- *
- */
-
-/** \file
- *
- * It is possible for one of the DMX "backend displays" to actually be
- * smaller than the dimensions of the backend X server.  Therefore, it
- * is possible for more than one of the DMX "backend displays" to be
- * physically located on the same backend X server.  This situation must
- * be detected so that cursor motion can be handled in an expected
- * fashion.
- *
- * We could analyze the names used for the DMX "backend displays" (e.g.,
- * the names passed to the -display command-line parameter), but there
- * are many possible names for a single X display, and failing to detect
- * sameness leads to very unexpected results.  Therefore, whenever the
- * DMX server opens a window on a backend X server, a property value is
- * queried and set on that backend to detect when another window is
- * already open on that server.
- *
- * Further, it is possible that two different DMX server instantiations
- * both have windows on the same physical backend X server.  This case
- * is also detected so that pointer input is not taken from that
- * particular backend X server.
- *
- * The routines in this file handle the property management. */
-
-#ifdef HAVE_DMX_CONFIG_H
-#include <dmx-config.h>
-#endif
-
-#include "dmx.h"
-#include "dmxprop.h"
-#include "dmxlog.h"
-
-/** Holds the window id of all DMX windows on the backend X server. */
-#define DMX_ATOMNAME "DMX_NAME"
-
-/** The identification string of this DMX server */
-#define DMX_IDENT    "Xdmx"
-
-extern char *display;
-
-static int dmxPropertyErrorHandler(Display *dpy, XErrorEvent *ev)
-{
-    return 0;
-}
-
-static const unsigned char *dmxPropertyIdentifier(void)
-{
-                                /* RATS: These buffers are only used in
-                                 * length-limited calls. */
-    char          hostname[256];
-    static char   buf[128];
-    static int    initialized = 0;
-
-    if (initialized++) return (unsigned char *)buf;
-    
-    XmuGetHostname(hostname, sizeof(hostname));
-    XmuSnprintf(buf, sizeof(buf), "%s:%s:%s", DMX_IDENT, hostname, display);
-    return (unsigned char *)buf;
-}
-
-/** Starting with the \a start screen, iterate over all of the screens
- * on the same physical X server as \a start, calling \a f with the
- * screen and the \a closure.  (The common case is that \a start is the
- * only DMX window on the backend X server.) */
-void *dmxPropertyIterate(DMXScreenInfo *start,
-                         void *(*f)(DMXScreenInfo *dmxScreen, void *),
-                         void *closure)
-{
-    DMXScreenInfo *pt;
-
-    if (!start->next) {
-        if (!start->beDisplay) return NULL;
-        return f(start, closure);
-    }
-
-    for (pt = start->next; /* condition at end of loop */; pt = pt->next) {
-        void *retval;
-        /* beDisplay ban be NULL if a screen was detached */
-        dmxLog(dmxDebug, "pt = %p\n", pt);
-        dmxLog(dmxDebug, "pt->beDisplay = %p\n", pt->beDisplay);
-        if (pt->beDisplay && (retval = f(pt, closure))) return retval;
-        if (pt == start) break;
-    }
-    return NULL;
-}
-
-/** Returns 0 if this is the only Xdmx session on the display; 1
- * otherwise. */
-static int dmxPropertyCheckOtherServers(DMXScreenInfo *dmxScreen, Atom atom)
-{
-    Display       *dpy    = dmxScreen->beDisplay;
-    XTextProperty tp;
-    XTextProperty tproot;
-    const char    *pt;
-    int           retcode = 0;
-    char          **list  = NULL;
-    int           count   = 0;
-    int           i;
-    int           (*dmxOldHandler)(Display *, XErrorEvent *);
-
-    if (!dpy)
-	return 0;
-
-    if (!XGetTextProperty(dpy, RootWindow(dpy,0), &tproot, atom)
-        || !tproot.nitems) return 0;
-    
-                                /* Ignore BadWindow errors for this
-                                 * routine because the window id stored
-                                 * in the property might be old */
-    dmxOldHandler = XSetErrorHandler(dmxPropertyErrorHandler);
-    for (pt = (const char *)tproot.value; pt && *pt; pt = pt ? pt + 1 : NULL) {
-        if ((pt = strchr(pt, ','))) {
-            Window win = strtol(pt+1, NULL, 10);
-            if (XGetTextProperty(dpy, win, &tp, atom) && tp.nitems) {
-                if (!strncmp((char *)tp.value, DMX_IDENT, strlen(DMX_IDENT))) {
-                    int flag = 0;
-                    for (i = 0; i < count; i++)
-                        if (!strcmp(list[i], (char *)tp.value)) {
-                            ++flag;
-                            break;
-                        }
-                    if (flag) continue;
-                    ++retcode;
-                    dmxLogOutputWarning(dmxScreen,
-                                        "%s also running on %s\n",
-                                        tp.value, dmxScreen->name);
-                    list = xrealloc(list, ++count * sizeof(*list));
-                    list[count-1] = xalloc(tp.nitems + 2);
-                    strncpy(list[count-1], (char *)tp.value, tp.nitems + 1);
-                }
-                XFree(tp.value);
-            }
-        }
-    }
-    XSetErrorHandler(dmxOldHandler);
-
-    for (i = 0; i < count; i++) xfree(list[i]);
-    xfree(list);
-    XFree(tproot.value);
-    if (!retcode)
-        dmxLogOutput(dmxScreen, "No Xdmx server running on backend\n");
-    return retcode;
-}
-
-/** Returns NULL if this is the only Xdmx window on the display.
- * Otherwise, returns a pointer to the dmxScreen of the other windows on
- * the display. */
-static DMXScreenInfo *dmxPropertyCheckOtherWindows(DMXScreenInfo *dmxScreen,
-                                                   Atom atom)
-{
-    Display             *dpy = dmxScreen->beDisplay;
-    const unsigned char *id  = dmxPropertyIdentifier();
-    XTextProperty       tproot;
-    XTextProperty       tp;
-    const char          *pt;
-    int                 (*dmxOldHandler)(Display *, XErrorEvent *);
-
-    if (!dpy)
-	return NULL;
-
-    if (!XGetTextProperty(dpy, RootWindow(dpy,0), &tproot, atom)
-        || !tproot.nitems) return 0;
-
-                                /* Ignore BadWindow errors for this
-                                 * routine because the window id stored
-                                 * in the property might be old */
-    dmxOldHandler = XSetErrorHandler(dmxPropertyErrorHandler);
-    for (pt = (const char *)tproot.value; pt && *pt; pt = pt ? pt + 1 : NULL) {
-        if ((pt = strchr(pt, ','))) {
-            Window win = strtol(pt+1, NULL, 10);
-            if (XGetTextProperty(dpy, win, &tp, atom) && tp.nitems) {
-                dmxLog(dmxDebug,"On %s/%lu: %s\n",
-                       dmxScreen->name, win, tp.value);
-                if (!strncmp((char *)tp.value, (char *)id,
-                             strlen((char *)id))) {
-                    int idx;
-                    
-                    if (!(pt = strchr((char *)tp.value, ','))) continue;
-                    idx = strtol(pt+1, NULL, 10);
-                    if (idx < 0 || idx >= dmxNumScreens) continue;
-                    if (dmxScreens[idx].scrnWin != win) continue;
-                    XSetErrorHandler(dmxOldHandler);
-                    return &dmxScreens[idx];
-                }
-                XFree(tp.value);
-            }
-        }
-    }
-    XSetErrorHandler(dmxOldHandler);
-    XFree(tproot.value);
-    return 0;
-}
-
-/** Returns 0 if this is the only Xdmx session on the display; 1
- * otherwise. */
-int dmxPropertyDisplay(DMXScreenInfo *dmxScreen)
-{
-    Atom                atom;
-    const unsigned char *id  = dmxPropertyIdentifier();
-    Display             *dpy = dmxScreen->beDisplay;
-
-    if (!dpy)
-	return 0;
-
-    atom = XInternAtom(dpy, DMX_ATOMNAME, False);
-    if (dmxPropertyCheckOtherServers(dmxScreen, atom)) {
-        dmxScreen->shared = 1;
-        return 1;
-    }
-    XChangeProperty(dpy, RootWindow(dpy,0), atom, XA_STRING, 8,
-                    PropModeReplace, id, strlen((char *)id));
-    return 0;
-}
-
-/** Returns 1 if the dmxScreen and the display in \a name are on the
- * same display, or 0 otherwise.  We can't just compare the display
- * names because there can be multiple synonyms for the same display,
- * some of which cannot be determined without accessing the display
- * itself (e.g., domain aliases or machines with multiple NICs). */
-int dmxPropertySameDisplay(DMXScreenInfo *dmxScreen, const char *name)
-{
-    Display             *dpy0  = dmxScreen->beDisplay;
-    Atom                atom0;
-    XTextProperty       tp0;
-    Display             *dpy1  = NULL;
-    Atom                atom1;
-    XTextProperty       tp1;
-    int                 retval = 0;
-
-    if (!dpy0)
-	return 0;
-
-    tp0.nitems = 0;
-    tp1.nitems = 0;
-
-    if ((atom0 = XInternAtom(dpy0, DMX_ATOMNAME, True)) == None) {
-        dmxLog(dmxWarning, "No atom on %s\n", dmxScreen->name);
-        return 0;
-    }
-    if (!XGetTextProperty(dpy0, RootWindow(dpy0,0), &tp0, atom0)
-        || !tp0.nitems) {
-        dmxLog(dmxWarning, "No text property on %s\n", dmxScreen->name);
-        return 0;
-    }
-
-    if (!(dpy1 = XOpenDisplay(name))) {
-        dmxLog(dmxWarning, "Cannot open %s\n", name);
-        goto cleanup;
-    }
-    atom1 = XInternAtom(dpy1, DMX_ATOMNAME, True);
-    if (atom1 == None) {
-        dmxLog(dmxDebug, "No atom on %s\n", name);
-        goto cleanup;
-    }
-    if (!XGetTextProperty(dpy1, RootWindow(dpy1,0), &tp1, atom1)
-        || !tp1.nitems) {
-        dmxLog(dmxDebug, "No text property on %s\n", name);
-        goto cleanup;
-    }
-    if (!strcmp((char *)tp0.value, (char *)tp1.value)) retval = 1;
-
-  cleanup:
-    if (tp0.nitems) XFree(tp0.value);
-    if (tp1.nitems) XFree(tp1.value);
-    if (dpy1)       XCloseDisplay(dpy1);
-    return retval;
-}
-
-/** Prints a log message if \a dmxScreen is on the same backend X server
- * as some other DMX backend (output) screen.  Modifies the property
- * (#DMX_ATOMNAME) on the backend X server to reflect the creation of \a
- * dmxScreen.
- *
- * The root window of the backend X server holds a list of window ids
- * for all DMX windows (on this DMX server or some other DMX server).
- *
- * This list can then be iterated, and the property for each window can
- * be examined.  This property contains the following tuple (no quotes):
- *
- * "#DMX_IDENT:<hostname running DMX>:<display name of DMX>,<screen number>"
- */
-void dmxPropertyWindow(DMXScreenInfo *dmxScreen)
-{
-    Atom                atom;
-    const unsigned char *id  = dmxPropertyIdentifier();
-    Display             *dpy = dmxScreen->beDisplay;
-    Window              win  = dmxScreen->scrnWin;
-    DMXScreenInfo       *other;
-    char                buf[128]; /* RATS: only used with XmuSnprintf */
-
-    if (!dpy)
-	return; /* FIXME: What should be done here if Xdmx is started
-		 * with this screen initially detached?
-		 */
-
-    atom = XInternAtom(dpy, DMX_ATOMNAME, False);
-    if ((other = dmxPropertyCheckOtherWindows(dmxScreen, atom))) {
-        DMXScreenInfo *tmp = dmxScreen->next;
-        dmxScreen->next    = (other->next ? other->next : other);
-        other->next        = (tmp         ? tmp         : dmxScreen);
-        dmxLog(dmxDebug, "%d/%s/%lu and %d/%s/%lu are on the same backend\n",
-               dmxScreen->index, dmxScreen->name, dmxScreen->scrnWin,
-               other->index, other->name, other->scrnWin);
-    }
-
-    XmuSnprintf(buf, sizeof(buf), ".%d,%lu", dmxScreen->index,
-                (long unsigned)win);
-    XChangeProperty(dpy, RootWindow(dpy,0), atom, XA_STRING, 8,
-                    PropModeAppend, (unsigned char *)buf, strlen(buf));
-
-    XmuSnprintf(buf, sizeof(buf), "%s,%d", id, dmxScreen->index);
-    XChangeProperty(dpy, win, atom, XA_STRING, 8,
-                    PropModeAppend, (unsigned char *)buf, strlen(buf));
-}
+/*

+ * Copyright 2002-2003 Red Hat Inc., Durham, North Carolina.

+ *

+ * All Rights Reserved.

+ *

+ * Permission is hereby granted, free of charge, to any person obtaining

+ * a copy of this software and associated documentation files (the

+ * "Software"), to deal in the Software without restriction, including

+ * without limitation on the rights to use, copy, modify, merge,

+ * publish, distribute, sublicense, and/or sell copies of the Software,

+ * and to permit persons to whom the Software is furnished to do so,

+ * subject to the following conditions:

+ *

+ * The above copyright notice and this permission notice (including the

+ * next paragraph) shall be included in all copies or substantial

+ * portions of the Software.

+ *

+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

+ * NON-INFRINGEMENT.  IN NO EVENT SHALL RED HAT AND/OR THEIR SUPPLIERS

+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

+ * SOFTWARE.

+ */

+

+/*

+ * Authors:

+ *   Rickard E. (Rik) Faith <faith@redhat.com>

+ *

+ */

+

+/** \file

+ *

+ * It is possible for one of the DMX "backend displays" to actually be

+ * smaller than the dimensions of the backend X server.  Therefore, it

+ * is possible for more than one of the DMX "backend displays" to be

+ * physically located on the same backend X server.  This situation must

+ * be detected so that cursor motion can be handled in an expected

+ * fashion.

+ *

+ * We could analyze the names used for the DMX "backend displays" (e.g.,

+ * the names passed to the -display command-line parameter), but there

+ * are many possible names for a single X display, and failing to detect

+ * sameness leads to very unexpected results.  Therefore, whenever the

+ * DMX server opens a window on a backend X server, a property value is

+ * queried and set on that backend to detect when another window is

+ * already open on that server.

+ *

+ * Further, it is possible that two different DMX server instantiations

+ * both have windows on the same physical backend X server.  This case

+ * is also detected so that pointer input is not taken from that

+ * particular backend X server.

+ *

+ * The routines in this file handle the property management. */

+

+#ifdef HAVE_DMX_CONFIG_H

+#include <dmx-config.h>

+#endif

+

+#include "dmx.h"

+#include "dmxprop.h"

+#include "dmxlog.h"

+

+/** Holds the window id of all DMX windows on the backend X server. */

+#define DMX_ATOMNAME "DMX_NAME"

+

+/** The identification string of this DMX server */

+#define DMX_IDENT    "Xdmx"

+

+extern char *display;

+

+static int dmxPropertyErrorHandler(Display *dpy, XErrorEvent *ev)

+{

+    return 0;

+}

+

+static const unsigned char *dmxPropertyIdentifier(void)

+{

+                                /* RATS: These buffers are only used in

+                                 * length-limited calls. */

+    char          hostname[256];

+    static char   buf[128];

+    static int    initialized = 0;

+

+    if (initialized++) return (unsigned char *)buf;

+    

+    XmuGetHostname(hostname, sizeof(hostname));

+    XmuSnprintf(buf, sizeof(buf), "%s:%s:%s", DMX_IDENT, hostname, display);

+    return (unsigned char *)buf;

+}

+

+/** Starting with the \a start screen, iterate over all of the screens

+ * on the same physical X server as \a start, calling \a f with the

+ * screen and the \a closure.  (The common case is that \a start is the

+ * only DMX window on the backend X server.) */

+void *dmxPropertyIterate(DMXScreenInfo *start,

+                         void *(*f)(DMXScreenInfo *dmxScreen, void *),

+                         void *closure)

+{

+    DMXScreenInfo *pt;

+

+    if (!start->next) {

+        if (!start->beDisplay) return NULL;

+        return f(start, closure);

+    }

+

+    for (pt = start->next; /* condition at end of loop */; pt = pt->next) {

+        void *retval;

+        /* beDisplay ban be NULL if a screen was detached */

+        dmxLog(dmxDebug, "pt = %p\n", pt);

+        dmxLog(dmxDebug, "pt->beDisplay = %p\n", pt->beDisplay);

+        if (pt->beDisplay && (retval = f(pt, closure))) return retval;

+        if (pt == start) break;

+    }

+    return NULL;

+}

+

+/** Returns 0 if this is the only Xdmx session on the display; 1

+ * otherwise. */

+static int dmxPropertyCheckOtherServers(DMXScreenInfo *dmxScreen, Atom atom)

+{

+    Display       *dpy    = dmxScreen->beDisplay;

+    XTextProperty tp;

+    XTextProperty tproot;

+    const char    *pt;

+    int           retcode = 0;

+    char          **list  = NULL;

+    int           count   = 0;

+    int           i;

+    int           (*dmxOldHandler)(Display *, XErrorEvent *);

+

+    if (!dpy)

+	return 0;

+

+    if (!XGetTextProperty(dpy, RootWindow(dpy,0), &tproot, atom)

+        || !tproot.nitems) return 0;

+    

+                                /* Ignore BadWindow errors for this

+                                 * routine because the window id stored

+                                 * in the property might be old */

+    dmxOldHandler = XSetErrorHandler(dmxPropertyErrorHandler);

+    for (pt = (const char *)tproot.value; pt && *pt; pt = pt ? pt + 1 : NULL) {

+        if ((pt = strchr(pt, ','))) {

+            Window win = strtol(pt+1, NULL, 10);

+            if (XGetTextProperty(dpy, win, &tp, atom) && tp.nitems) {

+                if (!strncmp((char *)tp.value, DMX_IDENT, strlen(DMX_IDENT))) {

+                    int flag = 0;

+                    for (i = 0; i < count; i++)

+                        if (!strcmp(list[i], (char *)tp.value)) {

+                            ++flag;

+                            break;

+                        }

+                    if (flag) continue;

+                    ++retcode;

+                    dmxLogOutputWarning(dmxScreen,

+                                        "%s also running on %s\n",

+                                        tp.value, dmxScreen->name);

+                    list = realloc(list, ++count * sizeof(*list));

+                    list[count-1] = malloc(tp.nitems + 2);

+                    strncpy(list[count-1], (char *)tp.value, tp.nitems + 1);

+                }

+                XFree(tp.value);

+            }

+        }

+    }

+    XSetErrorHandler(dmxOldHandler);

+

+    for (i = 0; i < count; i++) free(list[i]);

+    free(list);

+    XFree(tproot.value);

+    if (!retcode)

+        dmxLogOutput(dmxScreen, "No Xdmx server running on backend\n");

+    return retcode;

+}

+

+/** Returns NULL if this is the only Xdmx window on the display.

+ * Otherwise, returns a pointer to the dmxScreen of the other windows on

+ * the display. */

+static DMXScreenInfo *dmxPropertyCheckOtherWindows(DMXScreenInfo *dmxScreen,

+                                                   Atom atom)

+{

+    Display             *dpy = dmxScreen->beDisplay;

+    const unsigned char *id  = dmxPropertyIdentifier();

+    XTextProperty       tproot;

+    XTextProperty       tp;

+    const char          *pt;

+    int                 (*dmxOldHandler)(Display *, XErrorEvent *);

+

+    if (!dpy)

+	return NULL;

+

+    if (!XGetTextProperty(dpy, RootWindow(dpy,0), &tproot, atom)

+        || !tproot.nitems) return 0;

+

+                                /* Ignore BadWindow errors for this

+                                 * routine because the window id stored

+                                 * in the property might be old */

+    dmxOldHandler = XSetErrorHandler(dmxPropertyErrorHandler);

+    for (pt = (const char *)tproot.value; pt && *pt; pt = pt ? pt + 1 : NULL) {

+        if ((pt = strchr(pt, ','))) {

+            Window win = strtol(pt+1, NULL, 10);

+            if (XGetTextProperty(dpy, win, &tp, atom) && tp.nitems) {

+                dmxLog(dmxDebug,"On %s/%lu: %s\n",

+                       dmxScreen->name, win, tp.value);

+                if (!strncmp((char *)tp.value, (char *)id,

+                             strlen((char *)id))) {

+                    int idx;

+                    

+                    if (!(pt = strchr((char *)tp.value, ','))) continue;

+                    idx = strtol(pt+1, NULL, 10);

+                    if (idx < 0 || idx >= dmxNumScreens) continue;

+                    if (dmxScreens[idx].scrnWin != win) continue;

+                    XSetErrorHandler(dmxOldHandler);

+                    return &dmxScreens[idx];

+                }

+                XFree(tp.value);

+            }

+        }

+    }

+    XSetErrorHandler(dmxOldHandler);

+    XFree(tproot.value);

+    return 0;

+}

+

+/** Returns 0 if this is the only Xdmx session on the display; 1

+ * otherwise. */

+int dmxPropertyDisplay(DMXScreenInfo *dmxScreen)

+{

+    Atom                atom;

+    const unsigned char *id  = dmxPropertyIdentifier();

+    Display             *dpy = dmxScreen->beDisplay;

+

+    if (!dpy)

+	return 0;

+

+    atom = XInternAtom(dpy, DMX_ATOMNAME, False);

+    if (dmxPropertyCheckOtherServers(dmxScreen, atom)) {

+        dmxScreen->shared = 1;

+        return 1;

+    }

+    XChangeProperty(dpy, RootWindow(dpy,0), atom, XA_STRING, 8,

+                    PropModeReplace, id, strlen((char *)id));

+    return 0;

+}

+

+/** Returns 1 if the dmxScreen and the display in \a name are on the

+ * same display, or 0 otherwise.  We can't just compare the display

+ * names because there can be multiple synonyms for the same display,

+ * some of which cannot be determined without accessing the display

+ * itself (e.g., domain aliases or machines with multiple NICs). */

+int dmxPropertySameDisplay(DMXScreenInfo *dmxScreen, const char *name)

+{

+    Display             *dpy0  = dmxScreen->beDisplay;

+    Atom                atom0;

+    XTextProperty       tp0;

+    Display             *dpy1  = NULL;

+    Atom                atom1;

+    XTextProperty       tp1;

+    int                 retval = 0;

+

+    if (!dpy0)

+	return 0;

+

+    tp0.nitems = 0;

+    tp1.nitems = 0;

+

+    if ((atom0 = XInternAtom(dpy0, DMX_ATOMNAME, True)) == None) {

+        dmxLog(dmxWarning, "No atom on %s\n", dmxScreen->name);

+        return 0;

+    }

+    if (!XGetTextProperty(dpy0, RootWindow(dpy0,0), &tp0, atom0)

+        || !tp0.nitems) {

+        dmxLog(dmxWarning, "No text property on %s\n", dmxScreen->name);

+        return 0;

+    }

+

+    if (!(dpy1 = XOpenDisplay(name))) {

+        dmxLog(dmxWarning, "Cannot open %s\n", name);

+        goto cleanup;

+    }

+    atom1 = XInternAtom(dpy1, DMX_ATOMNAME, True);

+    if (atom1 == None) {

+        dmxLog(dmxDebug, "No atom on %s\n", name);

+        goto cleanup;

+    }

+    if (!XGetTextProperty(dpy1, RootWindow(dpy1,0), &tp1, atom1)

+        || !tp1.nitems) {

+        dmxLog(dmxDebug, "No text property on %s\n", name);

+        goto cleanup;

+    }

+    if (!strcmp((char *)tp0.value, (char *)tp1.value)) retval = 1;

+

+  cleanup:

+    if (tp0.nitems) XFree(tp0.value);

+    if (tp1.nitems) XFree(tp1.value);

+    if (dpy1)       XCloseDisplay(dpy1);

+    return retval;

+}

+

+/** Prints a log message if \a dmxScreen is on the same backend X server

+ * as some other DMX backend (output) screen.  Modifies the property

+ * (#DMX_ATOMNAME) on the backend X server to reflect the creation of \a

+ * dmxScreen.

+ *

+ * The root window of the backend X server holds a list of window ids

+ * for all DMX windows (on this DMX server or some other DMX server).

+ *

+ * This list can then be iterated, and the property for each window can

+ * be examined.  This property contains the following tuple (no quotes):

+ *

+ * "#DMX_IDENT:<hostname running DMX>:<display name of DMX>,<screen number>"

+ */

+void dmxPropertyWindow(DMXScreenInfo *dmxScreen)

+{

+    Atom                atom;

+    const unsigned char *id  = dmxPropertyIdentifier();

+    Display             *dpy = dmxScreen->beDisplay;

+    Window              win  = dmxScreen->scrnWin;

+    DMXScreenInfo       *other;

+    char                buf[128]; /* RATS: only used with XmuSnprintf */

+

+    if (!dpy)

+	return; /* FIXME: What should be done here if Xdmx is started

+		 * with this screen initially detached?

+		 */

+

+    atom = XInternAtom(dpy, DMX_ATOMNAME, False);

+    if ((other = dmxPropertyCheckOtherWindows(dmxScreen, atom))) {

+        DMXScreenInfo *tmp = dmxScreen->next;

+        dmxScreen->next    = (other->next ? other->next : other);

+        other->next        = (tmp         ? tmp         : dmxScreen);

+        dmxLog(dmxDebug, "%d/%s/%lu and %d/%s/%lu are on the same backend\n",

+               dmxScreen->index, dmxScreen->name, dmxScreen->scrnWin,

+               other->index, other->name, other->scrnWin);

+    }

+

+    XmuSnprintf(buf, sizeof(buf), ".%d,%lu", dmxScreen->index,

+                (long unsigned)win);

+    XChangeProperty(dpy, RootWindow(dpy,0), atom, XA_STRING, 8,

+                    PropModeAppend, (unsigned char *)buf, strlen(buf));

+

+    XmuSnprintf(buf, sizeof(buf), "%s,%d", id, dmxScreen->index);

+    XChangeProperty(dpy, win, atom, XA_STRING, 8,

+                    PropModeAppend, (unsigned char *)buf, strlen(buf));

+}