Re: [PATCH] Enable git rev-list to parse --quiet

Hi,

On Fri, 18 Jul 2008, Nick Andrew wrote:

I want to automatically (e.g. in crontab) update a git repo to the 
latest HEAD from a remote branch ... but with the possibility that the 
local repo has local changes, and I want no chance of merge failure. In 
other words, "git fetch remote; git merge origin/master" and only do the 
merge if it's a fast-forward. If there are any local commits, or local 
uncommitted changes, then leave the local working tree alone.

So my idea was to use "git rev-list --quiet master ^origin/master" and 
check the exit code; if zero do "git merge origin/master". Without a 
working "--quiet" nor exit code I can pipe the output to "wc -l" but is 
there a more efficient/reliable way to implement the requirement?

Yes. Check if "$(git rev-parse master)" is different from "$(git rev-parse 
origin/master)" (to avoid unnecessary merging), and then that "$(git 
merge-base master origin/master)" is equal to "$(git rev-parse master)".

Note: this is plumbing, meant for scripting (which is exactly your 
scenario).  Do not teach this to new Git users.

Ciao,
Dscho