Alexandre Julliard : shell32: Avoid infinite loop in _SHExpandEnvironmentStrings.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: ceea5bda14ecf4c8ce262fc7ab88df49e500bc38
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=ceea5bda14ecf4c8ce262fc7a...

Author: Alexandre Julliard <julliard(a)winehq.org>
Date:   Thu Sep  6 12:59:45 2018 +0200

shell32: Avoid infinite loop in _SHExpandEnvironmentStrings.

Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>

---

 dlls/shell32/shellpath.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/dlls/shell32/shellpath.c b/dlls/shell32/shellpath.c
index afd6340..dccfbba 100644
--- a/dlls/shell32/shellpath.c
+++ b/dlls/shell32/shellpath.c
@@ -3855,22 +3855,15 @@ static HRESULT _SHExpandEnvironmentStrings(LPCWSTR szSrc, LPWSTR szDest)
         }
         else
         {
-            DWORD ret = ExpandEnvironmentStringsW(szSrc, szDest, MAX_PATH);
+            DWORD ret = ExpandEnvironmentStringsW(szTemp, szDest, MAX_PATH);
 
             if (ret > MAX_PATH)
                 hr = E_NOT_SUFFICIENT_BUFFER;
             else if (ret == 0)
                 hr = HRESULT_FROM_WIN32(GetLastError());
-            else
-                hr = S_OK;
-        }
-        if (SUCCEEDED(hr) && szDest[0] == '%')
-            strcpyW(szTemp, szDest);
-        else
-        {
-            /* terminate loop */
-            szTemp[0] = '\0';
+            else if (!strcmpW( szTemp, szDest )) break;  /* nothing expanded */
         }
+        if (SUCCEEDED(hr)) strcpyW(szTemp, szDest);
     }
 end:
     if (key)