Avoid NULL dereference if cursor position changes during a mode change.

1 files changed, 10 insertions, 4 deletions

diff --git a/src/i830_cursor.c b/src/i830_cursor.c
index b3736490..2cb069cc 100644
--- a/src/i830_cursor.c
+++ b/src/i830_cursor.c
@@ -1,4 +1,4 @@
-
+/* -*- c-basic-offset: 3 -*- */
 /**************************************************************************
 
 Copyright 1998-1999 Precision Insight, Inc., Cedar Park, Texas.
@@ -398,9 +398,15 @@ I830SetCursorPosition(ScrnInfoPtr pScrn, int x, int y)
    x -= pScrn->frameX0;
    y -= pScrn->frameY0;
 
-   /* Clamp the cursor position to the visible screen area */
-   if (x >= pScrn->currentMode->HDisplay) x = pScrn->currentMode->HDisplay - 1;
-   if (y >= pScrn->currentMode->VDisplay) y = pScrn->currentMode->VDisplay - 1;
+   /* Clamp the cursor position to the visible screen area.  Ignore this if we
+    * are doing motion (with SilkenMouse) while the currentMode being changed.
+    */
+   if (pScrn->currentMode != NULL) {
+     if (x >= pScrn->currentMode->HDisplay)
+       x = pScrn->currentMode->HDisplay - 1;
+     if (y >= pScrn->currentMode->VDisplay)
+       y = pScrn->currentMode->VDisplay - 1;
+   }
    if (x <= -I810_CURSOR_X) x = -I810_CURSOR_X + 1;
    if (y <= -I810_CURSOR_Y) y = -I810_CURSOR_Y + 1;