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

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi,

On Sun, 5 Jul 2020, 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.

Thank you for those references. I did try to make sure that b914084007
would not regress on anything, but apparently I failed to verify the final
form. Since all it did was to remove `#if 0`...`#endif` guards, it was
unfortunately quite easy for this regression to slip in.

IIRC the original code inside those guards was modeled closely after
`execv_dashed_external()`, but it does not really look very much like it
anymore now, does it? (And it looks as if 2b296c93d49
(execv_dashed_external: use child_process struct, 2017-01-06) was
responsible for that.)

In any case, thank you for the patch, it looks good to me!

Ciao,
Dscho

>
> Signed-off-by: Trygve Aaberge <trygveaa@gmail.com>
> ---
>  git.c         | 2 +-
>  run-command.c | 1 +
>  run-command.h | 1 +
>  3 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/git.c b/git.c
> index a2d337eed7..c8336773e3 100644
> --- a/git.c
> +++ b/git.c
> @@ -767,7 +767,7 @@ static int run_argv(int *argcp, const char ***argv)
>  			 * OK to return. Otherwise, we just pass along the status code.
>  			 */
>  			i = run_command_v_opt_tr2(args.argv, RUN_SILENT_EXEC_FAILURE |
> -						  RUN_CLEAN_ON_EXIT, "git_alias");
> +						  RUN_CLEAN_ON_EXIT | RUN_WAIT_AFTER_CLEAN, "git_alias");
>  			if (i >= 0 || errno != ENOENT)
>  				exit(i);
>  			die("could not execute builtin %s", **argv);
> diff --git a/run-command.c b/run-command.c
> index 9b3a57d1e3..a735e380a9 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -1039,6 +1039,7 @@ int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
>  	cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
>  	cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
>  	cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
> +	cmd.wait_after_clean = opt & RUN_WAIT_AFTER_CLEAN ? 1 : 0;
>  	cmd.dir = dir;
>  	cmd.env = env;
>  	cmd.trace2_child_class = tr2_class;
> diff --git a/run-command.h b/run-command.h
> index 191dfcdafe..ef3071a565 100644
> --- a/run-command.h
> +++ b/run-command.h
> @@ -229,6 +229,7 @@ int run_auto_gc(int quiet);
>  #define RUN_SILENT_EXEC_FAILURE 8
>  #define RUN_USING_SHELL 16
>  #define RUN_CLEAN_ON_EXIT 32
> +#define RUN_WAIT_AFTER_CLEAN 64
>
>  /**
>   * Convenience functions that encapsulate a sequence of
> --
> 2.27.0
>
>