locking bug in glib:g_main_context_iterate()

[Matthias Drochner <M Drochner fz-juelich de>]

Hi -
in g_main_context_iterate(), the function can be left with the
context unlocked in some cases. This leads to double unlocking
of mutexes which might lead to diagnostic printouts or program
aborts, depending on the thread library.
The appended patch fixes it for me. (It only considers the
G_THREADS_ENABLED case; one might rearrange things slightly
for sanity.)

best regards
Matthias


$NetBSD: patch-ai,v 1.13 2007/01/10 14:57:33 drochner Exp $

--- glib/gmain.c.orig	2007-01-10 14:36:51.000000000 +0100
+++ glib/gmain.c
@@ -2619,13 +2619,13 @@ g_main_context_iterate (GMainContext *co
     {
       gboolean got_ownership;
       
+      LOCK_CONTEXT (context);
+
       g_return_val_if_fail (g_thread_supported (), FALSE);
 
       if (!block)
 	return FALSE;
 
-      LOCK_CONTEXT (context);
-      
       if (!context->cond)
 	context->cond = g_cond_new ();
           
@@ -2635,7 +2635,6 @@ g_main_context_iterate (GMainContext *co
 
       if (!got_ownership)
 	{
-	  UNLOCK_CONTEXT (context);
 	  return FALSE;
 	}
     }