From de95d8ee197a0bb738037195997d754a20e10254 Mon Sep 17 00:00:00 2001
From: Adam Jackson <ajax@nwnk.net>
Date: Fri, 18 Nov 2005 18:02:24 +0000
Subject: [PATCH] Bug #4859: Don't segfault on bad DDC read. (Tony Houghton)

---
 hw/xfree86/ddc/xf86DDC.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/hw/xfree86/ddc/xf86DDC.c b/hw/xfree86/ddc/xf86DDC.c
index f526cb484..36b214644 100644
--- a/hw/xfree86/ddc/xf86DDC.c
+++ b/hw/xfree86/ddc/xf86DDC.c
@@ -216,12 +216,15 @@ xf86DoEDID_DDC2(int scrnIndex, I2CBusPtr pBus)
 #ifdef DEBUG
     if (!tmp)
 	ErrorF("Cannot interpret EDID block\n");
-    ErrorF("Sections to follow: %i\n",tmp->no_sections);
+    else
+        ErrorF("Sections to follow: %i\n",tmp->no_sections);
 #endif
-    VDIF_Block = 
-	VDIFRead(scrnIndex, pBus, EDID1_LEN * (tmp->no_sections + 1));    
-    tmp->vdif = xf86InterpretVdif(VDIF_Block);
-
+    if (tmp) {
+        VDIF_Block = 
+            VDIFRead(scrnIndex, pBus, EDID1_LEN * (tmp->no_sections + 1));    
+        tmp->vdif = xf86InterpretVdif(VDIF_Block);
+    }
+    
     return tmp;
 }