Re: [PATCH] git-gui: Perform rescan on window focus-in

> The function is not documented, and I only started spelunking the code a
> couple days back, so I'll try to answer with what I know. It might not be
> the full picture.
> 
> Running git-gui --trace, these commands are executed during a rescan:
> 
> /usr/lib/git-core/git-rev-parse --verify HEAD
> /usr/lib/git-core/git-update-index -q --unmerged --ignore-missing --refresh
> 
> Since I'm not too familiar with the details of these, I'll let you be the
> judge on how expensive these operations are. But I'll add that rescans are
> pretty fast on my relatively slow hard disk.

> ui_do_rescan changes the focus to the first diff. It is executed when you
> press F5 or choose Rescan from the menu. do_rescan does not do that.
> 
> Resetting to first diff on focus change will get annoying when you are in
> the middle of looking at some other file. do_rescan just updates the
> software state without changing what file you are looking at or where in
> that file you are looking at.