Sebastian Lackner : shlwapi: Fix incorrect usage of CompareString in StrRStrIW.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 1b672e55ce738c5e02bd8c77df5dbf4668b7e30f
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=1b672e55ce738c5e02bd8c77df5dbf4668b7e30f

Author: Sebastian Lackner <sebastian at fds-team.de>
Date:   Wed Nov 19 08:31:40 2014 +0100

shlwapi: Fix incorrect usage of CompareString in StrRStrIW.

---

 dlls/shlwapi/string.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/dlls/shlwapi/string.c b/dlls/shlwapi/string.c
index 316dd3f..9ba6038 100644
--- a/dlls/shlwapi/string.c
+++ b/dlls/shlwapi/string.c
@@ -625,6 +625,7 @@ LPSTR WINAPI StrRStrIA(LPCSTR lpszStr, LPCSTR lpszEnd, LPCSTR lpszSearch)
  */
 LPWSTR WINAPI StrRStrIW(LPCWSTR lpszStr, LPCWSTR lpszEnd, LPCWSTR lpszSearch)
 {
+  LPWSTR lpszRet = NULL;
   INT iLen;
 
   TRACE("(%s,%s)\n", debugstr_w(lpszStr), debugstr_w(lpszSearch));
@@ -632,18 +633,23 @@ LPWSTR WINAPI StrRStrIW(LPCWSTR lpszStr, LPCWSTR lpszEnd, LPCWSTR lpszSearch)
   if (!lpszStr || !lpszSearch || !*lpszSearch)
     return NULL;
 
+  iLen = strlenW(lpszSearch);
+
   if (!lpszEnd)
     lpszEnd = lpszStr + strlenW(lpszStr);
+  else /* reproduce the broken behaviour on Windows */
+    lpszEnd += min(iLen - 1, lstrlenW(lpszEnd));
 
-  iLen = strlenW(lpszSearch);
-
-  while (lpszEnd > lpszStr)
+  while (lpszStr + iLen <= lpszEnd && *lpszStr)
   {
-    lpszEnd--;
-    if (!StrCmpNIW(lpszEnd, lpszSearch, iLen))
-      return (LPWSTR)lpszEnd;
+    if (!ChrCmpIW(*lpszSearch, *lpszStr))
+    {
+      if (!StrCmpNIW(lpszStr, lpszSearch, iLen))
+        lpszRet = (LPWSTR)lpszStr;
+    }
+    lpszStr++;
   }
-  return NULL;
+  return lpszRet;
 }
 
 /*************************************************************************