composer/composer — pull request #899 by Seldaek (2012-07-11 18:27:35+00:00)
Title: Prevent seeing dev versions as equal when they are not, fixes #848

I think it makes sense that the only case we want to select a dev- version is on an exact match (i.e. the two constraints having == & branch names are actually equal), this won't prevent selecting the master branch with `>1` and other ranges since that's converted to 9999999-dev.