David Faure authored Aug 01, 2018 and Brad King committed Aug 01, 2018

On systems with umask 022, this function would set permissions
to 664 and restore them to 644 at the end, every single time it was
called (which is many times on e.g. install_manifest.txt).

The intent of the code was to make non-writable files temporarily
writable and to restore permissions in the end, but really, if it's
already user-writable there's no point in toggling this back and forth.