[+cc Junio, whose code this is touching] On Sun, May 21, 2017 at 12:17:06AM -0500, Tyler Brazier wrote:
> This script explains and tests what's going on: > https://gist.github.com/tylerbrazier/4478e76fe44bf6657d4d3da6c789531d > > pull is failing because it shortcuts to --ff-only then calls > run_merge(), which does not know how to autostash. Removing the > shortcut fixes the problem: So I guess the ideal solution would be for us to do the autostash ourselves, run the fast-forward merge, and then pop the stash. In theory that's just "git stash push" followed by "git stash pop", but looking at the implementation in git-rebase.sh, it looks like it's a little more complicated than that. Disabling the optimization sounds like a reasonable interim workaround, but... > diff --git a/builtin/pull.c b/builtin/pull.c > index dd1a4a94e..225a59f5f 100644 > --- a/builtin/pull.c > +++ b/builtin/pull.c > @@ -868,11 +868,6 @@ int cmd_pull(int argc, const char **argv, const > char *prefix) > head = lookup_commit_reference(orig_head.hash); > commit_list_insert(head, &list); > merge_head = lookup_commit_reference(merge_heads.oid[0].hash); > - if (is_descendant_of(merge_head, list)) { > - /* we can fast-forward this without invoking rebase */ > - opt_ff = "--ff-only"; > - return run_merge(); > - } ...we can probably restrict it to when autostash is in use, like: /* * If this is a fast-forward, we can skip calling rebase and * just do the merge ourselves. But we don't know about * autostash, so use the real rebase command when it's in effect. */ if (!autostash && is_descendant_of(merge_head, list)) { opt_ff = "--ff-only"; return run_merge(); } AFAICT from the commit introducing this code (33b842a1e9), and the surrounding discussion: http://public-inbox.org/git/of95d98cb6.47969c1c-onc1257fe1.0058d980-c1257fe1.00599...@dakosy.de/T/#u this is purely an optimization to avoid invoking rebase, so it's OK to skip (and interestingly, the autostash question was raised in that thread but not resolved). But I notice on the run_merge() code path that we do still invoke git-merge. And rebase has been getting faster as it is moved to C code itself. So is this optimization even worth doing anymore? -Peff
