This stuff sucks. I'd like to just replace the dash with a directory division or tilde character. But this makes the code even more complicated, unless we can figure out how to migrate the taps.
We allow homebrew/dupes for instance, rather than Homebrew/dupes. Because nobody likes shifting in the terminal.
In the process of doing this I discovered some case-insensitive filesystem bugs we have avoided before because I had the foresight to mandate lowercase in formula names. GitHub considers Homebrew and homebrew to be different (even though you can't create both). So we had to allow case insensitivity in tap input. I have made it now so the resulting directory however is lowercased, neatly avoiding the issue. And so we also downcase tap arguments when applying them to tap directories or formula.
For when the symlink for a tap already exists and points to the thing we are about to symlink. This can happen, mostly because my code has sucked, but since the filesystem can be edited by the user at whim, it's possible then too.
Fixes:
$ brew tap adamv/alt
...blah blah blah..
$ brew tap josegonzalez/php
...blah blah blah...
Warning: Could not tap josegonzalez/php/php over mxcl/master/php
Where it should be "over adamv/alt/php".
The symlinks taps write to Formula show up in git status, but this trick prevents this. brew-(un)tap maintain a .gitignore in Formula that contains all the symlinks brew-tap creates.
We add the .gitignore to the root .gitignore and TADA! Magic.
