Returns an error if trying to write to a stream opened for read.

dlls/ole32/stg_stream.c

@@ -412,6 +412,9 @@ HRESULT WINAPI StgStreamImpl_Write(
   TRACE("(%p, %p, %ld, %p)\n",
 	iface, pv, cb, pcbWritten);
  
+  if (!(This->grfMode & STGM_WRITE))
+     return STG_E_ACCESSDENIED; 
+
   /*
    * If the caller is not interested in the number of bytes written,
    * we use another buffer to avoid "if" statements in the code.

dlls/ole32/storage32.c

@@ -336,6 +336,7 @@ HRESULT WINAPI StorageBaseImpl_OpenStream(
     
     if (newStream!=0)
     {
+      newStream->grfMode = grfMode;
       *ppstm = (IStream*)newStream;
 
       /*

dlls/ole32/storage32.h

@@ -626,7 +626,7 @@ struct StgStreamImpl
    */
   BlockChainStream*      bigBlockChain;
   SmallBlockChainStream* smallBlockChain;
-  
+  DWORD grfMode; 
 };
 
 /*