From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 11 Feb 2026 21:53:45 GMT
Subject: Re: [PATCH v4 2/3] alias: prepare for subsection aliases
Message-ID: <xmqq5x83rlp2.fsf@gitster.g>
In-Reply-To: <20260211211810.278806-3-jonatan@jontes.page>

Jonatan Holmgren <jonatan@jontes.page> writes:

> Switch git_unknown_cmd_config() from skip_prefix() to
> parse_config_key() for alias parsing. This properly handles the
> three-level config key structure and prepares for the new
> alias.*.command subsection syntax in the next commit.
>
> This is a compatibility break: the alias configuration parser used
> to be overly permissive and accepted "alias.<subsection>.<key>" as
> defining an alias "<subsection>.<key>". With this change,
> alias.<subsection>.<key> entries are silently ignored (unless <key>
> is "command", which will be given meaning in the next commit).
>
> This behavior was arguably a bug, since config subsections were never
> intended to work this way for aliases, and aliases with dots in their
> names have never been documented or intentionally supported.
>
> Signed-off-by: Jonatan Holmgren <jonatan@jontes.page>
> ---
>  help.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)

Very well explained.

>
> diff --git a/help.c b/help.c
> index 0bdb7ca10f..eccd0c22f8 100644
> --- a/help.c
> +++ b/help.c
> @@ -573,7 +573,8 @@ static int git_unknown_cmd_config(const char *var, const char *value,
>  				  void *cb)
>  {
>  	struct help_unknown_cmd_config *cfg = cb;
> -	const char *p;
> +	const char *subsection, *key;
> +	size_t subsection_len;
>  
>  	if (!strcmp(var, "help.autocorrect")) {
>  		int v = parse_autocorrect(value);
> @@ -588,8 +589,11 @@ static int git_unknown_cmd_config(const char *var, const char *value,
>  	}
>  
>  	/* Also use aliases for command lookup */
> -	if (skip_prefix(var, "alias.", &p))
> -		add_cmdname(&cfg->aliases, p, strlen(p));
> +	if (!parse_config_key(var, "alias", &subsection, &subsection_len,
> +			      &key)) {
> +		if (!subsection)
> +			add_cmdname(&cfg->aliases, key, strlen(key));
> +	}
>  
>  	return 0;
>  }