[dgorbachev] 52887: [WIN32K] Do not go beyond the MouseHistoryOfMoves[] bounds. Fixes a crash in Win32k.

Author: dgorbachev
Date: Tue Jul 26 03:24:48 2011
New Revision: 52887

URL: http://svn.reactos.org/svn/reactos?rev=52887&view=rev
Log:
[WIN32K]
Do not go beyond the MouseHistoryOfMoves[] bounds. Fixes a crash in Win32k.

Modified:
    trunk/reactos/subsystems/win32/win32k/ntuser/msgqueue.c

Modified: trunk/reactos/subsystems/win32/win32k/ntuser/msgqueue.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/nt…
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/ntuser/msgqueue.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/ntuser/msgqueue.c [iso-8859-1] Tue Jul 26
03:24:48 2011
@@ -616,7 +616,8 @@
    MouseHistoryOfMoves[gcur_count].y = Msg->pt.y;
    MouseHistoryOfMoves[gcur_count].time = Msg->time;
    MouseHistoryOfMoves[gcur_count].dwExtraInfo = dwExtraInfo;
-   if (gcur_count++ == 64) gcur_count = 0; // 0 - 63 is 64, FIFO forwards.
+   if (++gcur_count == ARRAYSIZE(MouseHistoryOfMoves))
+      gcur_count = 0; // 0 - 63 is 64, FIFO forwards.
 }
 
 //