[glib] make sure g_set_prgname() gets called only once

[Sven Herzberg <herzi src gnome org>]

commit 3dab24828edd8ebfd6d6c8bb20c181fc0d5650a1
Author: Sven Herzberg <herzi gnome-de org>
Date:   Fri Oct 23 14:49:38 2009 +0200

    make sure g_set_prgname() gets called only once
    
    * glib/gutils.c: copy the call-once statement from g_set_application_name();
      Fixes Bug #563627: g_get_prgname() threadsafety

 glib/gutils.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)
---
diff --git a/glib/gutils.c b/glib/gutils.c
index 8b7bfe8..b5e9c19 100644
--- a/glib/gutils.c
+++ b/glib/gutils.c
@@ -1968,10 +1968,17 @@ g_get_prgname (void)
 void
 g_set_prgname (const gchar *prgname)
 {
+  gboolean already_set = FALSE;
+
   G_LOCK (g_prgname);
-  g_free (g_prgname);
-  g_prgname = g_strdup (prgname);
+  if (g_prgname)
+    already_set = TRUE;
+  else
+    g_prgname = g_strdup (prgname);
   G_UNLOCK (g_prgname);
+
+  if (already_set)
+    g_warning ("g_set_prgname() called multiple times");
 }
 
 G_LOCK_DEFINE_STATIC (g_application_name);
@@ -2038,7 +2045,7 @@ g_set_application_name (const gchar *application_name)
   G_UNLOCK (g_application_name);
 
   if (already_set)
-    g_warning ("g_set_application() name called multiple times");
+    g_warning ("g_set_application_name() called multiple times");
 }
 
 /**