ole32: Fix crash when calling CreateStream on read only storage.

dlls/ole32/storage32.c

@@ -979,6 +979,10 @@ static HRESULT WINAPI StorageBaseImpl_CreateStream(
       (grfMode & STGM_TRANSACTED))
     return STG_E_INVALIDFUNCTION;
 
+  /* Can't create a stream on read-only storage */
+  if ( STGM_ACCESS_MODE( This->openFlags ) == STGM_READ )
+    return STG_E_ACCESSDENIED;
+
   /*
    * Check that we're compatible with the parent's storage mode
    * if not in transacted mode

dlls/ole32/tests/storage32.c

@@ -1302,13 +1302,11 @@ void test_readonly(void)
         ok(hr == S_OK, "should succeed, res=%x\n", hr);
         if (SUCCEEDED(hr))
         {
-#if 0 /* crashes on Wine */
             /* CreateStream on read-only storage, name exists */
             hr = IStorage_CreateStream( stg2, streamW, STGM_CREATE | STGM_SHARE_EXCLUSIVE | STGM_READ, 0, 0, &stream );
             ok(hr == STG_E_ACCESSDENIED, "should fail, res=%x\n", hr);
             if (SUCCEEDED(hr))
                 IStream_Release(stream);
-#endif
 
             /* CreateStream on read-only storage, name does not exist */
             hr = IStorage_CreateStream( stg2, storageW, STGM_CREATE | STGM_SHARE_EXCLUSIVE | STGM_READ, 0, 0, &stream );