don't die on bad atom name

2002-06-08  Havoc Pennington  <hp@pobox.com>

	* src/xprops.c (meta_prop_get_utf8_string): don't die on bad atom
	name

	* src/display.c (meta_display_close): don't unmanage windows here,
	do it in screen_free and then closing the display unmanages
	windows as a side effect of unmanaging the screen
	(meta_display_unmanage_screen): new function
	(process_selection_clear, process_selection_request): handle
	selection stuff
	(meta_spew_event): don't crash on client message containing
	invalid atom
	(meta_spew_event): don't crash on property notify with invalid
	atom

	* src/main.c (main): add --replace option to replace existing
	window manager.

	* src/screen.c: implement holding manager selection.

	* src/display.c (meta_display_open): add new selection-related
	atoms.

9 files changed, 463 insertions, 28 deletions

diff --git a/ChangeLog b/ChangeLog
index 770cb563..3a283928 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,29 @@
 2002-06-08  Havoc Pennington  <hp@pobox.com>
 
+	* src/xprops.c (meta_prop_get_utf8_string): don't die on bad atom
+	name
+
+	* src/display.c (meta_display_close): don't unmanage windows here,
+	do it in screen_free and then closing the display unmanages
+	windows as a side effect of unmanaging the screen
+	(meta_display_unmanage_screen): new function
+	(process_selection_clear, process_selection_request): handle
+	selection stuff
+	(meta_spew_event): don't crash on client message containing
+	invalid atom
+	(meta_spew_event): don't crash on property notify with invalid
+	atom
+
+	* src/main.c (main): add --replace option to replace existing
+	window manager.
+
+	* src/screen.c: implement holding manager selection.
+
+	* src/display.c (meta_display_open): add new selection-related
+	atoms.
+
+2002-06-08  Havoc Pennington  <hp@pobox.com>
+
 	* src/screen.c (meta_screen_new): select keypress/keyrelease
 	events on root window, this may fix the bug where keybindings
 	didn't work if you didn't have a focused window.
diff --git a/src/display.c b/src/display.c
index 53d9b640..1dcdb948 100644
--- a/src/display.c
+++ b/src/display.c
@@ -71,7 +71,10 @@ static guint32 event_get_time           (MetaDisplay    *display,
                                          XEvent         *event);
 static void    process_pong_message     (MetaDisplay    *display,
                                          XEvent         *event);
-
+static void    process_selection_request (MetaDisplay   *display,
+                                          XEvent        *event);
+static void    process_selection_clear   (MetaDisplay   *display,
+                                          XEvent        *event);
 
 static gint
 unsigned_long_equal (gconstpointer v1,
@@ -217,7 +220,13 @@ meta_display_open (const char *name)
     "WM_CLIENT_MACHINE",
     "_NET_WM_WORKAREA",
     "_NET_SHOW_DESKTOP",
-    "_NET_DESKTOP_LAYOUT"
+    "_NET_DESKTOP_LAYOUT",
+    "MANAGER",
+    "TARGETS",
+    "MULTIPLE",
+    "TIMESTAMP",
+    "VERSION",
+    "ATOM_PAIR"
   };
   Atom atoms[G_N_ELEMENTS(atom_names)];
   
@@ -340,6 +349,12 @@ meta_display_open (const char *name)
   display->atom_net_wm_workarea = atoms[56];
   display->atom_net_show_desktop = atoms[57];
   display->atom_net_desktop_layout = atoms[58];
+  display->atom_manager = atoms[59];
+  display->atom_targets = atoms[60];
+  display->atom_multiple = atoms[61];
+  display->atom_timestamp = atoms[62];
+  display->atom_version = atoms[63];
+  display->atom_atom_pair = atoms[64];
   
   /* Offscreen unmapped window used for _NET_SUPPORTING_WM_CHECK,
    * created in screen_new
@@ -529,26 +544,11 @@ meta_display_list_windows (MetaDisplay *display)
 void
 meta_display_close (MetaDisplay *display)
 {
-  GSList *winlist;
   GSList *tmp;
   
   if (display->error_traps > 0)
     meta_bug ("Display closed with error traps pending\n");
 
-  winlist = meta_display_list_windows (display);
-  
-  /* Unmanage all windows */
-  meta_display_grab (display);
-  tmp = winlist;
-  while (tmp != NULL)
-    {      
-      meta_window_free (tmp->data);
-      
-      tmp = tmp->next;
-    }
-  g_slist_free (winlist);
-  meta_display_ungrab (display);
-
   if (display->autoraise_timeout_id != 0)
     {
       g_source_remove (display->autoraise_timeout_id);
@@ -1373,8 +1373,18 @@ event_callback (XEvent   *event,
         }
       break;
     case SelectionClear:
+      /* do this here instead of at end of function
+       * so we can return
+       */
+      display->current_time = CurrentTime;
+      process_selection_clear (display, event);
+      /* Note that processing that may have resulted in
+       * closing the display... so return right away.
+       */
+      return FALSE;
       break;
     case SelectionRequest:
+      process_selection_request (display, event);
       break;
     case SelectionNotify:
       break;
@@ -1899,7 +1909,7 @@ meta_spew_event (MetaDisplay *display,
         extra = g_strdup_printf ("atom: %s state: %s",
                                  str ? str : "(unknown atom)",
                                  state);
-        XFree (str);
+        meta_XFree (str);
       }
       break;
     case SelectionClear:
@@ -1925,7 +1935,7 @@ meta_spew_event (MetaDisplay *display,
         extra = g_strdup_printf ("type: %s format: %d\n",
                                  str ? str : "(unknown atom)",
                                  event->xclient.format);
-        XFree (str);
+        meta_XFree (str);
       }
       break;
     case MappingNotify:
@@ -2989,3 +2999,249 @@ meta_rectangle_intersect (MetaRectangle *src1,
   return return_val;
 }
 
+static MetaScreen*
+find_screen_for_selection (MetaDisplay *display,
+                           Window       owner,
+                           Atom         selection)
+{  
+  GSList *tmp;  
+  
+  tmp = display->screens;
+  while (tmp != NULL)
+    {
+      MetaScreen *screen = tmp->data;
+      
+      if (screen->wm_sn_selection_window == owner &&
+          screen->wm_sn_atom == selection)
+        return screen;
+  
+      tmp = tmp->next;
+    }
+
+  return NULL;
+}
+
+/* from fvwm2, Copyright Dominik Vogt I assume, but it
+ * was unmarked.
+ */
+static gboolean
+convert_property (MetaDisplay *display,
+                  MetaScreen  *screen,
+                  Window       w,
+                  Atom         target,
+                  Atom         property)
+{
+#define N_TARGETS 4
+  Atom conversion_targets[N_TARGETS];
+  long icccm_version[] = { 2, 0 };
+
+  conversion_targets[0] = display->atom_targets;
+  conversion_targets[1] = display->atom_multiple;
+  conversion_targets[2] = display->atom_timestamp;
+  conversion_targets[3] = display->atom_version;
+
+  meta_error_trap_push (display);
+  if (target == display->atom_targets)
+    XChangeProperty (display->xdisplay, w, property,
+		     XA_ATOM, 32, PropModeReplace,
+		     (unsigned char *)conversion_targets, N_TARGETS);
+  else if (target == display->atom_timestamp)
+    XChangeProperty (display->xdisplay, w, property,
+		     XA_INTEGER, 32, PropModeReplace,
+		     (unsigned char *)&screen->wm_sn_timestamp, 1);
+  else if (target == display->atom_version)
+    XChangeProperty (display->xdisplay, w, property,
+		     XA_INTEGER, 32, PropModeReplace,
+		     (unsigned char *)icccm_version, 2);
+  else
+    {
+      meta_error_trap_pop (display);
+      return FALSE;
+    }
+  
+  if (meta_error_trap_pop (display) != Success)
+    return FALSE;
+
+  /* Be sure the PropertyNotify has arrived so we
+   * can send SelectionNotify
+   */
+  XSync (display->xdisplay, False);
+
+  return TRUE;
+}
+
+/* from fvwm2, Copyright Dominik Vogt I assume, but it
+ * was unmarked.
+ */
+static void
+process_selection_request (MetaDisplay   *display,
+                           XEvent        *event)
+{
+  XSelectionEvent reply;
+  MetaScreen *screen;
+
+  screen = find_screen_for_selection (display,
+                                      event->xselectionrequest.owner,
+                                      event->xselectionrequest.selection);
+
+  if (screen == NULL)
+    {
+      char *str;
+      
+      meta_error_trap_push (display);
+      str = XGetAtomName (display->xdisplay,
+                          event->xselectionrequest.selection);
+      meta_error_trap_pop (display);
+      
+      meta_verbose ("Selection request with selection %s window 0x%lx not a WM_Sn selection we recognize\n",
+                    str ? str : "(bad atom)", event->xselectionrequest.owner);
+      
+      meta_XFree (str);
+
+      return;
+    }
+  
+  reply.type = SelectionNotify;
+  reply.display = display->xdisplay;
+  reply.requestor = event->xselectionrequest.requestor;
+  reply.selection = event->xselectionrequest.selection;
+  reply.target = event->xselectionrequest.target;
+  reply.property = None;
+  reply.time = event->xselectionrequest.time;
+
+  if (event->xselectionrequest.target == display->atom_multiple)
+    {
+      if (event->xselectionrequest.property != None)
+        {
+          Atom type, *adata;
+          int i, format;
+          unsigned long num, rest;
+          unsigned char *data;
+
+          meta_error_trap_push (display);
+          XGetWindowProperty (display->xdisplay,
+                              event->xselectionrequest.requestor,
+                              event->xselectionrequest.property, 0, 256, False,
+                              display->atom_atom_pair,
+                              &type, &format, &num, &rest, &data);
+          if (meta_error_trap_pop (display) == Success)
+            {              
+              /* FIXME: to be 100% correct, should deal with rest > 0,
+               * but since we have 4 possible targets, we will hardly ever
+               * meet multiple requests with a length > 8
+               */
+              adata = (Atom*)data;
+              i = 0;
+              while (i < (int) num)
+                {
+                  if (!convert_property (display, screen,
+                                         event->xselectionrequest.requestor,
+                                         adata[i], adata[i+1]))
+                    adata[i+1] = None;
+                  i += 2;
+                }
+
+              meta_error_trap_push (display);
+              XChangeProperty (display->xdisplay,
+                               event->xselectionrequest.requestor,
+                               event->xselectionrequest.property,
+                               display->atom_atom_pair,
+                               32, PropModeReplace, data, num);
+              meta_error_trap_pop (display);
+              meta_XFree (data);
+            }
+        }
+    }
+  else
+    {
+      if (event->xselectionrequest.property == None)
+        event->xselectionrequest.property = event->xselectionrequest.target;
+      
+      if (convert_property (display, screen,
+                            event->xselectionrequest.requestor,
+                            event->xselectionrequest.target,
+                            event->xselectionrequest.property))
+        reply.property = event->xselectionrequest.property;
+    }
+
+  XSendEvent (display->xdisplay,
+              event->xselectionrequest.requestor,
+              False, 0L, (XEvent*)&reply);
+
+  meta_verbose ("Handled selection request\n");
+}
+
+static void
+process_selection_clear (MetaDisplay   *display,
+                         XEvent        *event)
+{
+  /* We need to unmanage the screen on which we lost the selection */
+  MetaScreen *screen;
+
+  screen = find_screen_for_selection (display,
+                                      event->xselectionclear.window,
+                                      event->xselectionclear.selection);
+  
+
+  if (screen != NULL)
+    {
+      meta_verbose ("Got selection clear for screen %d on display %s\n",
+                    screen->number, display->name);
+      
+      meta_display_unmanage_screen (display, screen);
+
+      /* display and screen may both be invalid memory... */
+      
+      return;
+    }
+
+  {
+    char *str;
+            
+    meta_error_trap_push (display);
+    str = XGetAtomName (display->xdisplay,
+                        event->xselectionclear.selection);
+    meta_error_trap_pop (display);
+
+    meta_verbose ("Selection clear with selection %s window 0x%lx not a WM_Sn selection we recognize\n",
+                  str ? str : "(bad atom)", event->xselectionclear.window);
+
+    meta_XFree (str);
+  }
+}
+
+void
+meta_display_unmanage_screen (MetaDisplay *display,
+                              MetaScreen  *screen)
+{
+  meta_verbose ("Unmanaging screen %d on display %s\n",
+                screen->number, display->name);
+  
+  g_return_if_fail (g_slist_find (display->screens, screen) != NULL);
+  
+  meta_screen_free (screen);
+  display->screens = g_slist_remove (display->screens, screen);
+
+  if (display->screens == NULL)
+    meta_display_close (display);
+}
+
+void
+meta_display_unmanage_windows_for_screen (MetaDisplay *display,
+                                          MetaScreen  *screen)
+{
+  GSList *tmp;
+  GSList *winlist;
+
+  winlist = meta_display_list_windows (display);
+
+  /* Unmanage all windows */
+  tmp = winlist;
+  while (tmp != NULL)
+    {      
+      meta_window_free (tmp->data);
+      
+      tmp = tmp->next;
+    }
+  g_slist_free (winlist);
+}
diff --git a/src/display.h b/src/display.h
index 92a94a09..52b8292f 100644
--- a/src/display.h
+++ b/src/display.h
@@ -131,6 +131,12 @@ struct _MetaDisplay
   Atom atom_net_wm_workarea;
   Atom atom_net_show_desktop;
   Atom atom_net_desktop_layout;
+  Atom atom_manager;
+  Atom atom_targets;
+  Atom atom_multiple;
+  Atom atom_timestamp;
+  Atom atom_version;
+  Atom atom_atom_pair;
   
   /* This is the actual window from focus events,
    * not the one we last set
@@ -225,6 +231,12 @@ void          meta_display_grab                (MetaDisplay *display);
 void          meta_display_ungrab              (MetaDisplay *display);
 gboolean      meta_display_is_double_click     (MetaDisplay *display);
 
+void          meta_display_unmanage_screen     (MetaDisplay *display,
+                                                MetaScreen  *screen);
+
+void          meta_display_unmanage_windows_for_screen (MetaDisplay *display,
+                                                        MetaScreen  *screen);
+
 /* A given MetaWindow may have various X windows that "belong"
  * to it, such as the frame window.
  */
diff --git a/src/main.c b/src/main.c
index d5009e2a..c0522059 100644
--- a/src/main.c
+++ b/src/main.c
@@ -127,7 +127,9 @@ main (int argc, char **argv)
           strcmp (arg, "-?") == 0)
         usage ();
       else if (strcmp (arg, "--sm-disable") == 0)
-        disable_sm = TRUE; 
+        disable_sm = TRUE;
+      else if (strcmp (arg, "--replace") == 0)
+        meta_set_replace_current_wm (TRUE);
       else if (strstr (arg, "--display=") == arg)
         {
           const char *disp;
diff --git a/src/screen.c b/src/screen.c
index 758ddd55..e5b68ca1 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -1,7 +1,10 @@
 /* Metacity X screen handler */
 
 /* 
- * Copyright (C) 2001 Havoc Pennington
+ * Copyright (C) 2001, 2002 Havoc Pennington
+ * Copyright (C) 2002 Red Hat Inc.
+ * Some ICCCM manager selection code derived from fvwm2,
+ * Copyright (C) 2001 Dominik Vogt and fvwm2 team
  * 
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -38,6 +41,7 @@
 #include <X11/Xatom.h>
 #include <locale.h>
 #include <string.h>
+#include <stdio.h>
 
 static char* get_screen_name (MetaDisplay *display,
                               int          number);
@@ -168,6 +172,14 @@ meta_screen_new (MetaDisplay *display,
   Window xroot;
   Display *xdisplay;
   XWindowAttributes attr;
+  Window new_wm_sn_owner;
+  Window current_wm_sn_owner;
+  gboolean replace_current_wm;
+  Atom wm_sn_atom;
+  char buf[128];
+  Time manager_timestamp;
+  
+  replace_current_wm = meta_get_replace_current_wm ();
   
   /* Only display->name, display->xdisplay, and display->error_traps
    * can really be used in this function, since normally screens are
@@ -191,7 +203,98 @@ meta_screen_new (MetaDisplay *display,
       return NULL;
     }
 
-  /* Select our root window events */
+  sprintf (buf, "WM_S%d", number);
+  wm_sn_atom = XInternAtom (xdisplay, buf, False);  
+  
+  current_wm_sn_owner = XGetSelectionOwner (xdisplay, wm_sn_atom);
+
+  if (current_wm_sn_owner != None)
+    {
+      XSetWindowAttributes attrs;
+      
+      if (!replace_current_wm)
+        {
+          meta_warning (_("Screen %d on display \"%s\" already has a window manager; try using the --replace option to override the current window manager.\n"),
+                        number, display->name);
+
+          return NULL;
+        }
+
+      /* We want to find out when the current selection owner dies */
+      meta_error_trap_push (display);
+      attrs.event_mask = StructureNotifyMask;
+      XChangeWindowAttributes (xdisplay,
+                               current_wm_sn_owner, CWEventMask, &attrs);
+      if (meta_error_trap_pop (display) != Success)
+        current_wm_sn_owner = None; /* don't wait for it to die later on */
+    }
+
+  new_wm_sn_owner = XCreateSimpleWindow (xdisplay, xroot,
+                                         -100, -100, 1, 1, 0, 0, 0);
+
+  {
+    /* Generate a timestamp */
+    XSetWindowAttributes attrs;
+    XEvent event;
+
+    attrs.event_mask = PropertyChangeMask;
+    XChangeWindowAttributes (xdisplay, new_wm_sn_owner, CWEventMask, &attrs);
+    
+    XChangeProperty (xdisplay,
+                     new_wm_sn_owner, XA_WM_CLASS, XA_STRING, 8,
+                     PropModeAppend, NULL, 0);
+    XWindowEvent (xdisplay, new_wm_sn_owner, PropertyChangeMask, &event);
+    attrs.event_mask = NoEventMask;
+    XChangeWindowAttributes (display->xdisplay,
+                             new_wm_sn_owner, CWEventMask, &attrs);
+
+    manager_timestamp = event.xproperty.time;
+  }
+  
+  XSetSelectionOwner (xdisplay, wm_sn_atom, new_wm_sn_owner,
+                      manager_timestamp);
+
+  if (XGetSelectionOwner (xdisplay, wm_sn_atom) != new_wm_sn_owner)
+    {
+      meta_warning (_("Could not acquire window manager selection on screen %d display \"%s\"\n"),
+                    number, display->name);
+
+      XDestroyWindow (xdisplay, new_wm_sn_owner);
+      
+      return NULL;
+    }
+  
+  {
+    /* Send client message indicating that we are now the WM */
+    XClientMessageEvent ev;
+    
+    ev.type = ClientMessage;
+    ev.window = xroot;
+    ev.message_type = display->atom_manager;
+    ev.format = 32;
+    ev.data.l[0] = manager_timestamp;
+    ev.data.l[1] = wm_sn_atom;
+
+    XSendEvent (xdisplay, xroot, False, StructureNotifyMask, (XEvent*)&ev);
+  }
+
+  /* Wait for old window manager to go away */
+  if (current_wm_sn_owner != None)
+    {
+      XEvent event;
+
+      /* We sort of block infinitely here which is probably lame. */
+      
+      meta_verbose ("Waiting for old window manager to exit\n");
+      do
+        {
+          XWindowEvent (xdisplay, current_wm_sn_owner,
+                        StructureNotifyMask, &event);
+        }
+      while (event.type != DestroyNotify);
+    }
+  
+  /* select our root window events */
   meta_error_trap_push (display);
 
   /* We need to or with the existing event mask since
@@ -208,13 +311,16 @@ meta_screen_new (MetaDisplay *display,
                 FocusChangeMask | attr.your_event_mask);
   if (meta_error_trap_pop (display) != Success)
     {
-      meta_warning (_("Screen %d on display '%s' already has a window manager\n"),
+      meta_warning (_("Screen %d on display \"%s\" already has a window manager\n"),
                     number, display->name);
+
+      XDestroyWindow (xdisplay, new_wm_sn_owner);
+      
       return NULL;
     }
   
   screen = g_new (MetaScreen, 1);
-
+  
   screen->display = display;
   screen->number = number;
   screen->screen_name = get_screen_name (display, number);
@@ -226,6 +332,10 @@ meta_screen_new (MetaDisplay *display,
   screen->default_xvisual = DefaultVisualOfScreen (screen->xscreen);
   screen->default_depth = DefaultDepthOfScreen (screen->xscreen);
 
+  screen->wm_sn_selection_window = new_wm_sn_owner;
+  screen->wm_sn_atom = wm_sn_atom;
+  screen->wm_sn_timestamp = manager_timestamp;
+  
   screen->work_area_idle = 0;
 
   screen->rows_of_workspaces = 1;
@@ -385,7 +495,15 @@ meta_screen_new (MetaDisplay *display,
 
 void
 meta_screen_free (MetaScreen *screen)
-{  
+{
+  MetaDisplay *display;
+
+  display = screen->display;
+  
+  meta_display_grab (display);
+
+  meta_display_unmanage_windows_for_screen (display, screen);
+  
   meta_prefs_remove_listener (prefs_changed_callback, screen);
   
   meta_screen_ungrab_keys (screen);
@@ -397,14 +515,19 @@ meta_screen_free (MetaScreen *screen)
   meta_error_trap_push (screen->display);
   XSelectInput (screen->display->xdisplay, screen->xroot, 0);
   if (meta_error_trap_pop (screen->display) != Success)
-    meta_warning (_("Could not release screen %d on display '%s'\n"),
+    meta_warning (_("Could not release screen %d on display \"%s\"\n"),
                   screen->number, screen->display->name);
 
+  XDestroyWindow (screen->display->xdisplay,
+                  screen->wm_sn_selection_window);
+  
   if (screen->work_area_idle != 0)
     g_source_remove (screen->work_area_idle);
   
   g_free (screen->screen_name);
   g_free (screen);
+
+  meta_display_ungrab (display);
 }
 
 void
diff --git a/src/screen.h b/src/screen.h
index f9782037..b76d7ac1 100644
--- a/src/screen.h
+++ b/src/screen.h
@@ -60,6 +60,10 @@ struct _MetaScreen
 
   MetaCursor current_cursor;
 
+  Window wm_sn_selection_window;
+  Atom wm_sn_atom;
+  Time wm_sn_timestamp;
+  
   MetaXineramaScreenInfo *xinerama_infos;
   int n_xinerama_infos;
 
diff --git a/src/util.c b/src/util.c
index a48edf44..3c5c9855 100644
--- a/src/util.c
+++ b/src/util.c
@@ -31,6 +31,7 @@
 
 static gboolean is_verbose = FALSE;
 static gboolean is_debugging = FALSE;
+static gboolean replace_current = FALSE;
 static int no_prefix = 0;
 static FILE* logfile = NULL;
 
@@ -109,6 +110,18 @@ meta_set_debugging (gboolean setting)
   is_debugging = setting;
 }
 
+gboolean
+meta_get_replace_current_wm (void)
+{
+  return replace_current;
+}
+
+void
+meta_set_replace_current_wm (gboolean setting)
+{
+  replace_current = setting;
+}
+
 void
 meta_debug_spew (const char *format, ...)
 {
diff --git a/src/util.h b/src/util.h
index 52b87c97..2ba94d5f 100644
--- a/src/util.h
+++ b/src/util.h
@@ -30,7 +30,8 @@ gboolean meta_is_debugging (void);
 void     meta_set_debugging (gboolean setting);
 gboolean meta_is_syncing (void);
 void     meta_set_syncing (gboolean setting);
-
+gboolean meta_get_replace_current_wm (void);
+void     meta_set_replace_current_wm (gboolean setting);
 
 void meta_debug_spew (const char *format,
                       ...) G_GNUC_PRINTF (1, 2);
diff --git a/src/xprops.c b/src/xprops.c
index f5cd838a..bb539c30 100644
--- a/src/xprops.c
+++ b/src/xprops.c
@@ -280,7 +280,7 @@ meta_prop_get_utf8_string (MetaDisplay   *display,
       name = XGetAtomName (display->xdisplay, xatom);
       meta_warning (_("Property %s on window 0x%lx contained invalid UTF-8\n"),
                     name, xwindow);
-      XFree (name);
+      meta_XFree (name);
       XFree (str);
 
       return FALSE;