`webkit-patch upload` runs git-diff at least 3 times:
1) when finding ChangeLogs to parse for bug IDs
2) when running check-webkit-style (I think)
3) when creating the diff to present to the user for confirmation
There might be other instances of git-diff that I've missed.
It would be faster if we could just run git-diff once.
Yeah, I recently removed one of them (by sharing the one for prepare-ChangeLog with another one we do). We should be able to remove the one for check-webkit-style by passing it the list of changed files. However, passing them today gives you different output. We need to teach check-webkit-style to diff a set of files provided on the command line. It's not that much code.
I'm pretty sure we have another bug on this somewhere...
See bug 39207.