You might make some notes about old format headers and new format ones and the use_legacy_headers flag. I started off looking at packs so I knew about TYPE_AND_BASE128_SIZE. Next I wanted to write objects so I looked at sha1_file.c. If you don't look at the code closely write_binary_header() will lead you to believe that object files use TYPE_AND_BASE128_SIZE. It took me a couple of hours to notice use_legacy_headers and discover that it defaults to on. Jon Smirl jonsmirl@xxxxxxxxx - : send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html