…us return value
Pretty awesome. And the select(2) based implementation will fix a long-standing bug where the grit process will hang when a git process writes more than PIPE_BUF bytes to stderr or when the input written to the git process's stdin exceeds PIPE_BUF. The old popen3 based logic writes all of stdin, then reads all of stdout, then reads all of stderr so everything except stdout had to come in under PIPE_BUF. This hasn't been much of an issue but is critical to our plans on using `git cat-file --batch' and writing a bunch of SHA1s on stdin. Also moving toward using a common spawn method interface that's a compatible subset of the Process.spawn method built into Ruby >= 1.9.1. The hope is that most non-MRI platforms will eventually support Process.spawn out of the box and the ones that don't have backports.
This removes some overhead from all native git calls in the following ways: - Removes a fork previously performed by Open3, which double forks to avoid needing to Process::wait. - Removes the need to shell escape arguments, since the git process's argv is passed explicitly as an array. - Removes the /bin/sh process (1 fork/exec) Additionally, these changes allow obtaining the git process's exit status, available as $? after any native git command invocations.