From: Dana Jansens <danakj@orodu.net>
Date: Mon, 18 Feb 2008 21:44:41 +0000 (-0500)
Subject: Fix races that occur when a window id is destroyed and recreated very quickly. This... 
X-Git-Url: http://git.openbox.org/?p=dana%2Fxcompmgr.git;a=commitdiff_plain;h=93395847717133d0210877a1efa4f18ab632293b;ds=sidebyside

Fix races that occur when a window id is destroyed and recreated very quickly. This behaviour happens when restarting the window manager.

Don't use windows that are destroyed when restacking other windows or when handling events on a window id.  It is possible for the same window id to appear in the window list multiple times if it is destroyed then created before the destroy fade-out completes.
---

diff --git a/xcompmgr.c b/xcompmgr.c
index 291624b..276d1bd 100644
--- a/xcompmgr.c
+++ b/xcompmgr.c
@@ -100,6 +100,7 @@ typedef struct _win {
     unsigned int	opacity;
     wintype             windowType;
     unsigned long	damage_sequence;    /* sequence when damage was created */
+    Bool                destroyed;
 
     Bool                need_configure;
     XConfigureEvent     queue_configure;
@@ -779,7 +780,7 @@ find_win (Display *dpy, Window id)
     win	*w;
 
     for (w = list; w; w = w->next)
-	if (w->id == id)
+	if (w->id == id && !w->destroyed)
 	    return w;
     return 0;
 }
@@ -1513,7 +1514,7 @@ add_win (Display *dpy, Window id, Window prev)
     if (prev)
     {
 	for (p = &list; *p; p = &(*p)->next)
-	    if ((*p)->id == prev)
+	    if ((*p)->id == prev && !(*p)->destroyed)
 		break;
     }
     else
@@ -1553,6 +1554,7 @@ add_win (Display *dpy, Window id, Window prev)
     new->shadow_width = 0;
     new->shadow_height = 0;
     new->opacity = OPAQUE;
+    new->destroyed = False;
     new->need_configure = False;
 
     new->borderClip = None;
@@ -1586,7 +1588,7 @@ restack_win (Display *dpy, win *w, Window new_above)
 	/* rehook */
 	for (prev = &list; *prev; prev = &(*prev)->next)
 	{
-	    if ((*prev)->id == new_above)
+	    if ((*prev)->id == new_above && !(*prev)->destroyed)
 		break;
 	}
 	w->next = *prev;
@@ -1693,7 +1695,7 @@ finish_destroy_win (Display *dpy, Window id)
     win	**prev, *w;
 
     for (prev = &list; (w = *prev); prev = &w->next)
-	if (w->id == id)
+	if (w->id == id && w->destroyed)
 	{
             finish_unmap_win (dpy, w);
 	    *prev = w->next;
@@ -1733,6 +1735,8 @@ destroy_win (Display *dpy, Window id, Bool fade)
 {
     win *w = find_win (dpy, id);
 
+    if (w) w->destroyed = True;
+
 #if HAS_NAME_WINDOW_PIXMAP
     if (w && w->pixmap && fade && winTypeFade[w->windowType])
 	set_fade (dpy, w, w->opacity*1.0/OPAQUE, 0.0, fade_out_step,