++ gnome-screensaver-2.30.2/debian/patches/16_dont_crash_in_kvm.patch

Description: Don't crash when the XF86VM extension doesn't allow the gamma to be set
 On some systems where the XF86VM extension is present, the gamma value
 can be read successfully with XF86VidModeGetGamma but attempting to
 change the gamma value with XF86VidModeSetGamma will result in a
 BadValue error (eg, on KVM).

 Trap this error and abort the fade rather than crashing.
Bug-Ubuntu: https://launchpad.net/bugs/581864
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=618932
Forwarded: https://bugzilla.gnome.org/attachment.cgi?id=161276
Author: Chris Coulson <chris.coulson@canonical.com>

Index: gnome-screensaver-2.30.2/src/gs-fade.c
===================================================================
--- gnome-screensaver-2.30.2.orig/src/gs-fade.c	2010-11-15 16:35:43.078663002 +1100
+++ gnome-screensaver-2.30.2/src/gs-fade.c	2010-11-15 16:37:45.814662558 +1100
@@ -208,7 +208,13 @@
                         g2.blue = XF86_MIN_GAMMA;
                 }
 
+                gdk_error_trap_push ();
                 status = XF86VidModeSetGamma (GDK_DISPLAY (), screen, &g2);
+                gdk_flush ();
+                if (gdk_error_trap_pop ()) {
+                        gs_debug ("Failed to set gamma. Bailing out and aborting fade");
+                        return FALSE;        
+                }
         } else {
 
 # ifdef HAVE_XF86VMODE_GAMMA_RAMP
@@ -225,7 +231,13 @@
                         b[i] = gamma_info->b[i] * ratio;
                 }
 
+                gdk_error_trap_push ();
                 status = XF86VidModeSetGammaRamp (GDK_DISPLAY (), screen, gamma_info->size, r, g, b);
+                gdk_flush ();
+                if (gdk_error_trap_pop ()) {
+                        gs_debug ("Failed to set gamma. Bailing out and aborting fade");
+                        return FALSE;                
+                }
 
                 g_free (r);
                 g_free (g);
@@ -236,8 +248,6 @@
 # endif /* !HAVE_XF86VMODE_GAMMA_RAMP */
         }
 
-        gdk_flush ();
-
         return status;
 }
 
@@ -391,7 +401,7 @@
         screen_priv = &fade->priv->screen_priv[screen_idx];
         res = xf86_whack_gamma (screen_idx, screen_priv, alpha);
 
-        return TRUE;
+        return res;
 }
 #endif /* HAVE_XF86VMODE_GAMMA */