From 9d8f60cf818cfea0648cb693ef5642e9f30da3af Mon Sep 17 00:00:00 2001
From: Gregor Schneider <grschneider@gmail.com>
Date: Mon, 3 Aug 2009 16:15:40 +0000
Subject: [PATCH] - Fix mbslwr: increment pointer in both cases (prevents
 infinite loops) - Check for null character pointers, apply somewhat readable
 formatting - Add some useful header information See issue #4755 for more
 details.

svn path=/trunk/; revision=42363
---
 reactos/lib/sdk/crt/mbstring/mbslwr.c | 32 +++++++++++++++++----------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/reactos/lib/sdk/crt/mbstring/mbslwr.c b/reactos/lib/sdk/crt/mbstring/mbslwr.c
index d2ad5bcc3e2..10d5e11296c 100644
--- a/reactos/lib/sdk/crt/mbstring/mbslwr.c
+++ b/reactos/lib/sdk/crt/mbstring/mbslwr.c
@@ -1,12 +1,10 @@
 /*
  * COPYRIGHT:   See COPYING in the top level directory
  * PROJECT:     ReactOS system libraries
- * FILE:        lib/sdk/crt/mbstring/ismbpun.c
- * PURPOSE:
- * PROGRAMER:   
- * UPDATE HISTORY:
- *              05/30/08: Samuel Serapion adapted from PROJECT C Library
- *
+ * FILE:        lib/sdk/crt/mbstring/mbslwr.c
+ * PURPOSE:     Multibyte lowercase functions
+ * PROGRAMER:   Eric Kohl
+ *              Samuel Serapion, adapted from PROJECT C Library
  */
 
 #include <precomp.h>
@@ -33,14 +31,24 @@ unsigned int _mbctolower(unsigned int c)
  */
 unsigned char * _mbslwr(unsigned char *x)
 {
-    unsigned char  *y=x;
+    unsigned char *y=x;
 
-    while (*y) {
-        if (!_ismbblead(*y)) {
+    if (x == NULL)
+    {
+        return NULL;
+    }
+
+    while (*y) 
+    {
+        if (!_ismbblead(*y)) 
+        {
             *y = tolower(*y);
-	    } else {
-	        *y=_mbctolower(*(unsigned short *)y);
-	        y++;
+            y++;
+        } 
+        else
+        {
+            *y = _mbctolower(*(unsigned short *)y);
+            y++;
         }
     }
     return x;