Since `pinned?` was using `File#exists?`, broken symlinks left by force-upgraded
formulae made `pinned?` return false while `pin` returned with an error because
it could not overwrite the broken link. This is fixed by using `File#symlink?`
instead, which returns true for broken symlinks and false only when they do not
exist.
ClosesHomebrew/homebrew#18858.
Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
* Added `pin` et. al. to manpage.
* Added `brew pin` to `brew.1` * Added `brew unpin` to `brew.1`
* Added `brew list --pinned` to `brew.1`
* Added information about frozen formulae to `brew upgrade` in `brew.1`
* Added `pin` et.al. to completion scripts.
* Unpin formulae when uninstalling them
* Unpin and re-pin formulae when upgrading (avoids stale symlink)
References Homebrew/homebrew#18386.
ClosesHomebrew/homebrew#18515.
Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
