Larry Wall posted patch 1.3 to mod.sources on May 8, 1985. A number of versions followed over the years. It’s been a faithful alley for a long, long time. I’ve never had a problem with patch until I embarked on the 2.11BSD restoration project. In going over the logs very carefully, I’ve discovered a bug that bites this effort twice. It’s quite interesting to use 27 year old patches to find this bug while restoring a 29 year old OS...

source: HN