Fix boolean expression (XERCESC-1837)

git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@709141 13f79535-47bb-0310-9956-ffa450edef68

src/xercesc/internal/ReaderMgr.cpp

@@ -1057,7 +1057,7 @@ bool ReaderMgr::popReader()
     //  If there was a previous entity, and either the fThrowEOE flag is set
     //  or reader was marked as such, then throw an end of entity.
     //
-    if (prevEntity && fThrowEOE || prevReaderThrowAtEnd)
+    if (prevEntity && (fThrowEOE || prevReaderThrowAtEnd))
         throw EndOfEntityException(prevEntity, readerNum);
 
     while (true)