[SVN] r4083 - branches/SDL-1.2/src/video/Xext/Xxf86vm

[svn-owner at libsdl.org]

Author: icculus
Date: 2008-09-08 00:33:05 -0700 (Mon, 08 Sep 2008)
New Revision: 4083

Modified:
   branches/SDL-1.2/src/video/Xext/Xxf86vm/XF86VMode.c
Log:
Prevent crash from unaligned memory access on sparc64, etc.

Fixes Bugzilla #602. I suspect this will crash elsewhere if the system
 actually had modelines to report, though.


Modified: branches/SDL-1.2/src/video/Xext/Xxf86vm/XF86VMode.c
===================================================================
--- branches/SDL-1.2/src/video/Xext/Xxf86vm/XF86VMode.c	2008-09-06 04:31:34 UTC (rev 4082)
+++ branches/SDL-1.2/src/video/Xext/Xxf86vm/XF86VMode.c	2008-09-08 07:33:05 UTC (rev 4083)
@@ -214,6 +214,12 @@
     return True;
 }
 
+/* this is to prevent an unaligned memory write on CPUs that need that. */
+static void zap_ptr(char *ptr, size_t size)
+{
+    memset(ptr, '\0', size);
+}
+
 Bool
 SDL_NAME(XF86VidModeGetModeLine)(dpy, screen, dotclock, modeline)
     Display* dpy;
@@ -284,7 +290,7 @@
 	}
 	_XRead(dpy, (char*)modeline->private, modeline->privsize * sizeof(INT32));
     } else {
-	modeline->private = NULL;
+	zap_ptr((char *)&modeline->private, sizeof(modeline->private))
     }
     UnlockDisplay(dpy);
     SyncHandle();