hbons/SparkleShare — pull request #781 by carlosmn (2012-06-07 13:51:04+00:00)
Title: SparkleLib: Use rev-parse HEAD to determine latest commit

While `git log -1 --format=%H` does show the same data, it needs to
start up the revision walking machinery just to show the latest
commit's hash. `git rev-parse HEAD` tells us this commit's hash
without doing all the extra work.

Unscientific testing shows ~10ms vs. ~5ms with warm cache. Cold cache, a spinning disc or an OS where `mmap` isn't that great should make this difference larger. It's nothing ground-breaking, but it saves us some processing on each call.