From 2cee7ac6d94e2273499dc2c3e19885af40ca27f1 Mon Sep 17 00:00:00 2001
From: Mike McCormack <mike@codeweavers.com>
Date: Mon, 19 Jan 2004 21:44:02 +0000
Subject: [PATCH] Don't use CreateFileMapping on a zero length file.

---
 dlls/ole32/stg_bigblockfile.c | 39 +++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/dlls/ole32/stg_bigblockfile.c b/dlls/ole32/stg_bigblockfile.c
index d76602926d2..323f05df47a 100644
--- a/dlls/ole32/stg_bigblockfile.c
+++ b/dlls/ole32/stg_bigblockfile.c
@@ -222,23 +222,28 @@ 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);
-
-  if (!This->hfilemap)
-  {
-    CloseHandle(This->hfile);
-    return FALSE;
-  }
-
   This->filesize.s.LowPart = GetFileSize(This->hfile,
 					 &This->filesize.s.HighPart);
 
+  if( This->filesize.s.LowPart || This->filesize.s.HighPart )
+  {
+    /* create the file mapping object
+     */
+    This->hfilemap = CreateFileMappingA(This->hfile,
+                                        NULL,
+                                        This->flProtect,
+                                        0, 0,
+                                        NULL);
+
+    if (!This->hfilemap)
+    {
+      CloseHandle(This->hfile);
+      return FALSE;
+    }
+  }
+  else
+    This->hfilemap = NULL;
+
   This->maplist = NULL;
 
   TRACE("file len %lu\n", This->filesize.s.LowPart);
@@ -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