Index: code/missionui/missionscreencommon.cpp
===================================================================
--- code/missionui/missionscreencommon.cpp	(revision 5327)
+++ code/missionui/missionscreencommon.cpp	(working copy)
@@ -1712,6 +1712,7 @@
 	}
 
 	player_id = INTEL_SHORT( player_id );
+	Assert( offset += sizeof(player_id) < max_size );
 	memcpy(block+offset,&player_id,sizeof(player_id));
 	offset += sizeof(player_id);