Don't use CreateFileMapping on a zero length file.

dlls/ole32/stg_bigblockfile.c

@@ -222,22 +222,27 @@ static BOOL BIGBLOCKFILE_FileInit(LPBIGBLOCKFILE This, HANDLE hFile)
   if (This->hfile == INVALID_HANDLE_VALUE)
     return FALSE;
 
-  /* create the file mapping object
-   */
-  This->hfilemap = CreateFileMappingA(This->hfile,
-                                      NULL,
-                                      This->flProtect,
-                                      0, 0,
-                                      NULL);
+  This->filesize.s.LowPart = GetFileSize(This->hfile,
+					 &This->filesize.s.HighPart);
 
-  if (!This->hfilemap)
+  if( This->filesize.s.LowPart || This->filesize.s.HighPart )
   {
-    CloseHandle(This->hfile);
-    return FALSE;
-  }
+    /* create the file mapping object
+     */
+    This->hfilemap = CreateFileMappingA(This->hfile,
+                                        NULL,
+                                        This->flProtect,
+                                        0, 0,
+                                        NULL);
 
-  This->filesize.s.LowPart = GetFileSize(This->hfile,
-					 &This->filesize.s.HighPart);
+    if (!This->hfilemap)
+    {
+      CloseHandle(This->hfile);
+      return FALSE;
+    }
+  }
+  else
+    This->hfilemap = NULL;
 
   This->maplist = NULL;
 
@@ -420,7 +425,8 @@ void BIGBLOCKFILE_SetSize(LPBIGBLOCKFILE This, ULARGE_INTEGER newSize)
     /*
      * close file-mapping object, must be done before call to SetEndFile
      */
-    CloseHandle(This->hfilemap);
+    if( This->hfilemap )
+      CloseHandle(This->hfilemap);
     This->hfilemap = 0;
 
     /*
@@ -662,6 +668,9 @@ static BOOL BIGBLOCKFILE_MapPage(LPBIGBLOCKFILE This, MappedPage *page)
 	DWORD numBytesToMap;
 	DWORD desired_access;
 
+        if( !This->hfilemap )
+            return FALSE;
+
 	if (lowoffset + PAGE_SIZE > This->filesize.s.LowPart)
 	    numBytesToMap = This->filesize.s.LowPart - lowoffset;
 	else