[mutter] window: fix meta_window_is_remote across hostname changes

[Ray Strode <halfline src gnome org>]

commit 2cafb8be2d4346474b5bf90c318f58ccca49d83b
Author: Ray Strode <rstrode redhat com>
Date:   Wed Feb 20 15:17:21 2013 -0500

    window: fix meta_window_is_remote across hostname changes
    
    meta_window_is_remote compares a cached copy of the system hostname
    with the hostname of the client window
    (as presented by the WM_CLIENT_MACHINE property).
    
    Of course, the system hostname can change at any time, so caching
    it is wrong. Also, the WM_CLIENT_MACHINE property won't necessarily
    change when the system hostname changes, so comparing it with the
    new system hostname is wrong, too.
    
    This commit makes the code call gethostname() at the time
    WM_CLIENT_MACHINE is set, check whether it's remote then, and cache
    that value, rather than comparing potentially out of sync hostnames
    later.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=688716

 src/core/display-private.h |    1 -
 src/core/display.c         |    9 ---------
 src/core/window-private.h  |    3 +++
 src/core/window-props.c    |   19 +++++++++++++++++++
 src/core/window.c          |    7 ++-----
 5 files changed, 24 insertions(+), 15 deletions(-)
---
diff --git a/src/core/display-private.h b/src/core/display-private.h
index 99984e1..c4abbfa 100644
--- a/src/core/display-private.h
+++ b/src/core/display-private.h
@@ -93,7 +93,6 @@ struct _MetaDisplay
   
   char *name;
   Display *xdisplay;
-  char *hostname;
 
   Window leader_window;
   Window timestamp_pinging_window;
diff --git a/src/core/display.c b/src/core/display.c
index 2e522a9..b1e6543 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -466,7 +466,6 @@ meta_display_open (void)
   GSList *tmp;
   int i;
   guint32 timestamp;
-  char buf[257];
 
   /* A list of all atom names, so that we can intern them in one go. */
   char *atom_names[] = {
@@ -501,13 +500,6 @@ meta_display_open (void)
    */
   the_display->name = g_strdup (XDisplayName (NULL));
   the_display->xdisplay = xdisplay;
-  if (gethostname (buf, sizeof(buf)-1) == 0)
-    {
-      buf[sizeof(buf)-1] = '\0';
-      the_display->hostname = g_strdup (buf);
-    }
-  else
-    the_display->hostname = NULL;
   the_display->error_trap_synced_at_last_pop = TRUE;
   the_display->error_traps = 0;
   the_display->error_trap_handler = NULL;
@@ -1116,7 +1108,6 @@ meta_display_close (MetaDisplay *display,
   meta_display_free_window_prop_hooks (display);
   meta_display_free_group_prop_hooks (display);
   
-  g_free (display->hostname);
   g_free (display->name);
 
   meta_display_shutdown_keys (display);
diff --git a/src/core/window-private.h b/src/core/window-private.h
index 04ee110..311af19 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -346,6 +346,9 @@ struct _MetaWindow
   /* if TRUE, we are freezing updates during a resize */
   guint updates_frozen_for_resize : 1;
 
+  /* whether or not the window is from a program running on another machine */
+  guint is_remote : 1;
+
   /* if non-NULL, the bounds of the window frame */
   cairo_region_t *frame_bounds;
 
diff --git a/src/core/window-props.c b/src/core/window-props.c
index 7f44d17..b422563 100644
--- a/src/core/window-props.c
+++ b/src/core/window-props.c
@@ -37,6 +37,7 @@
  */
 
 #define _GNU_SOURCE
+#define _SVID_SOURCE /* for gethostname() */
 
 #include <config.h>
 #include "window-props.h"
@@ -48,6 +49,11 @@
 #include <unistd.h>
 #include <string.h>
 
+#ifndef HOST_NAME_MAX
+/* Solaris headers apparently don't define this so do so manually; #326745 */
+#define HOST_NAME_MAX 255
+#endif
+
 typedef void (* ReloadValueFunc) (MetaWindow    *window,
                                   MetaPropValue *value,
                                   gboolean       initial);
@@ -195,6 +201,19 @@ reload_wm_client_machine (MetaWindow    *window,
 
   meta_verbose ("Window has client machine \"%s\"\n",
                 window->wm_client_machine ? window->wm_client_machine : "unset");
+
+  if (window->wm_client_machine == NULL)
+    {
+      window->is_remote = FALSE;
+    }
+  else
+    {
+      char hostname[HOST_NAME_MAX + 1] = "";
+
+      gethostname (hostname, HOST_NAME_MAX + 1);
+
+      window->is_remote = g_strcmp0 (window->wm_client_machine, hostname) != 0;
+    }
 }
 
 static void
diff --git a/src/core/window.c b/src/core/window.c
index 19d1988..210cf22 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -1161,6 +1161,7 @@ meta_window_new_with_attrs (MetaDisplay       *display,
   window->role = NULL;
   window->sm_client_id = NULL;
   window->wm_client_machine = NULL;
+  window->is_remote = FALSE;
   window->startup_id = NULL;
 
   window->net_wm_pid = -1;
@@ -10895,11 +10896,7 @@ meta_window_get_client_machine (MetaWindow *window)
 gboolean
 meta_window_is_remote (MetaWindow *window)
 {
-  g_return_val_if_fail (META_IS_WINDOW (window), FALSE);
-
-  if (window->wm_client_machine != NULL)
-    return g_strcmp0 (window->wm_client_machine, window->display->hostname) != 0;
-  return FALSE;
+  return window->is_remote;
 }
 
 /**