fix for #29894, newsrc file corruption. need to truncate the newsrc when

we open it.  otherwise, if we go to write it out and it has gotten smaller,
we will leave garbage at the end of the file.  big thanks to Ken Dowling (kdowling@concentric.net) reporting this bug. a=jar

mailnews/news/src/nsNntpIncomingServer.cpp

@@ -194,7 +194,7 @@ nsNntpIncomingServer::WriteNewsrcFile()
         rv = newsrcFile->GetFileSpec(&newsrcFileSpec);
         if (NS_FAILED(rv)) return rv;
 
-        nsIOFileStream  newsrcStream(newsrcFileSpec /*, PR_CREATE_FILE */ );
+        nsIOFileStream newsrcStream(newsrcFileSpec, (PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE));
 
         nsCOMPtr<nsIEnumerator> subFolders;
         nsCOMPtr<nsIFolder> rootFolder;