Re: [PATCH 2/2] rerere: fix overeager gc

> 'rerere gc' prunes resolutions of conflicted merges that occurred long
> time ago, and when doing so it takes the creation time of the
> conflicted automerge results into account.  This can cause the loss of
> frequently used conflict resolutions (e.g. long-living topic branches
> are merged into a regularly rebuilt integration branch (think of git's
> pu)) when they become old enough to exceed 'rerere gc's threshold.
>
> To prevent the loss of valuable merge resolutions 'rerere' will (1)
> update the timestamp of the recorded conflict resolution (i.e.
> 'postimage') each time when encountering and resolving the same merge
> conflict, and (2) take this timestamp, i.e. the time of the last usage
> into account when gc'ing.

> +static time_t rerere_last_used_at(const char *name)
> +{
> +	struct stat st;
> +	return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
> +}