Re: [PATCH 1/2] Wait for child on signal death for aliases to builtins

[Jeff King <peff@peff.net>]

On Sun, Jul 05, 2020 at 12:18:37AM +0200, trygveaa@gmail.com wrote:

> From: Trygve Aaberge <trygveaa@gmail.com>
> 
> When you hit ^C all the processes in the tree receives it. When a git
> command uses a pager, git ignores this and waits until the pager quits.
> However, when using an alias there is an additional process in the tree
> which didn't ignore the signal. That caused it to exit which in turn
> caused the pager to exit. This fixes that for aliases to builtins.
> 
> This was originally fixed in 46df6906f3 (see that for a more in
> explanation), but broke by a regression in b914084007.

Good catch. The regression is technically in b914084007, but the real
culprit is the extra (commented out) code path added in ee4512ed48
(trace2: create new combined trace facility, 2019-02-22).

Your fix here looks good, but it does make me wonder if we could avoid
or shrink this duplicate code path. I.e., could it just do the logging
necessary but still leave the actual process spawn to the
execv_dashed_external() below. It may be hard to untangle, though, so
certainly this makes sense in the meantime.

A test would be nice, but I don't think it's very feasible for the same
reason mentioned in 46df6906f3.

-Peff