Sorry - nullptr doesn't work with the default Makefile and I don't trust the rest of the code to compile with -std=c++11 yet.

contrib/bobtoolz/DPatch.cpp

@@ -302,7 +302,7 @@ DPatch* DPatch::MergePatches( patch_merge_t merge_info, DPatch *p1, DPatch *p2 )
 
 	int newHeight = p1->height + p2->height - 1;
 	if ( newHeight > MAX_PATCH_HEIGHT ) {
-		return nullptr;
+		return NULL;
 	}
 
 	DPatch* newPatch = new DPatch();