Alex Henrie : kernel32: Avoid calling MultiByteToWideChar with invalid parameters.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 92b4979b3312f0d3a308c2c0a259fa0153612019
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=92b4979b3312f0d3a308c2c0a259fa0153612019

Author: Alex Henrie <alexhenrie24 at gmail.com>
Date:   Wed May 16 19:24:07 2012 -0600

kernel32: Avoid calling MultiByteToWideChar with invalid parameters.

---

 dlls/kernel32/locale.c |   57 +++++++++++++++++++++++++++++++----------------
 1 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/dlls/kernel32/locale.c b/dlls/kernel32/locale.c
index b506f15..380c616 100644
--- a/dlls/kernel32/locale.c
+++ b/dlls/kernel32/locale.c
@@ -2867,34 +2867,51 @@ INT WINAPI CompareStringA(LCID lcid, DWORD style,
 
     if (!(style & LOCALE_USE_CP_ACP)) locale_cp = get_lcid_codepage( lcid );
 
-    len1W = MultiByteToWideChar(locale_cp, 0, str1, len1, buf1W, 130);
-    if (len1W)
-        str1W = buf1W;
-    else
+    if (len1)
     {
-        len1W = MultiByteToWideChar(locale_cp, 0, str1, len1, NULL, 0);
-        str1W = HeapAlloc(GetProcessHeap(), 0, len1W * sizeof(WCHAR));
-        if (!str1W)
+        len1W = MultiByteToWideChar(locale_cp, 0, str1, len1, buf1W, 130);
+        if (len1W)
+            str1W = buf1W;
+        else
         {
-            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
-            return 0;
+            len1W = MultiByteToWideChar(locale_cp, 0, str1, len1, NULL, 0);
+            str1W = HeapAlloc(GetProcessHeap(), 0, len1W * sizeof(WCHAR));
+            if (!str1W)
+            {
+                SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+                return 0;
+            }
+            MultiByteToWideChar(locale_cp, 0, str1, len1, str1W, len1W);
         }
-        MultiByteToWideChar(locale_cp, 0, str1, len1, str1W, len1W);
     }
-    len2W = MultiByteToWideChar(locale_cp, 0, str2, len2, buf2W, 130);
-    if (len2W)
-        str2W = buf2W;
     else
     {
-        len2W = MultiByteToWideChar(locale_cp, 0, str2, len2, NULL, 0);
-        str2W = HeapAlloc(GetProcessHeap(), 0, len2W * sizeof(WCHAR));
-        if (!str2W)
+        len1W = 0;
+        str1W = buf1W;
+    }
+
+    if (len2)
+    {
+        len2W = MultiByteToWideChar(locale_cp, 0, str2, len2, buf2W, 130);
+        if (len2W)
+            str2W = buf2W;
+        else
         {
-            if (str1W != buf1W) HeapFree(GetProcessHeap(), 0, str1W);
-            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
-            return 0;
+            len2W = MultiByteToWideChar(locale_cp, 0, str2, len2, NULL, 0);
+            str2W = HeapAlloc(GetProcessHeap(), 0, len2W * sizeof(WCHAR));
+            if (!str2W)
+            {
+                if (str1W != buf1W) HeapFree(GetProcessHeap(), 0, str1W);
+                SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+                return 0;
+            }
+            MultiByteToWideChar(locale_cp, 0, str2, len2, str2W, len2W);
         }
-        MultiByteToWideChar(locale_cp, 0, str2, len2, str2W, len2W);
+    }
+    else
+    {
+        len2W = 0;
+        str2W = buf2W;
     }
 
     ret = CompareStringW(lcid, style, str1W, len1W, str2W, len2W);