Re: [PATCH v2 6/7] config: allow configuration of multiple hook error behavior

[Jeff King <peff@peff.net>]

On Tue, May 14, 2019 at 12:23:31AM +0000, brian m. carlson wrote:

> There are a variety of situations in which a user may want an error
> behavior for multiple hooks other than the default. Add a config option,
> hook.<name>.errorBehavior to allow users to customize this behavior on a
> per-hook basis. Provide options for the default behavior (exiting
> early), executing all hooks and succeeding if all hooks succeed, or
> executing all hooks and succeeding if any hook succeeds.

Thanks for using that naming scheme. I think if we do move to allowing
config-based hooks, the config schemes will mesh together well.

> +static int git_default_hook_config(const char *key, const char *value)
> +{
> +	const char *hook;
> +	size_t key_len;
> +	uintptr_t behavior;
> +
> +	key += strlen("hook.");
> +	if (strip_suffix(key, ".errorbehavior", &key_len)) {

There's an undocumented assumption that the caller has confirmed that
the key starts with "hook." here. Can we be a little more defensive and
do:

  if (skip_prefix(key, "hook.", &key))
	return 0;

here (we could even drop the check in git_default_config).

Or we could use parse_key(), which is designed for this:

  if (parse_key(key, "hook", &subsection, &subsection_len, &key) < 0 ||
      !subsection)
	return 0;
  if (!strcmp(key, "errorbehavior"))
	...

> +	/* Use -2 as sentinel because failure to exec is -1. */
> +	int ret = -2;

Maybe this would be simpler to follow by using an enum for the handler
return value?

Aside from these nits, the code looked sensible to me.

-Peff