Re: [PATCH v2 8/8] Use the early config machinery to expand aliases

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> On Sat, Jun 10, 2017 at 06:07:30AM -0400, Jeff King wrote:
>
>> But couldn't we just unconditionally do:
>> 
>>   setup_git_directory_gently();
>> 
>> here to move into the top-level if there is one, without caring about
>> cdup_dir at all?
>
> IOW, drop your patch 4, and then squash patches 7 and 8 into this:

That looks a lot simpler.

> diff --git a/alias.c b/alias.c
> index 3b90397a9..6bdc93630 100644
> --- a/alias.c
> +++ b/alias.c
> @@ -1,14 +1,31 @@
>  #include "cache.h"
>  
> +struct config_alias_data
> +{
> +	struct strbuf key;
> +	char *v;
> +};
> +
> +static int config_alias_cb(const char *key, const char *value, void *d)
> +{
> +	struct config_alias_data *data = d;
> +
> +	if (!strcmp(key, data->key.buf))
> +		return git_config_string((const char **)&data->v, key, value);
> +
> +	return 0;
> +}
> +
>  char *alias_lookup(const char *alias)
>  {
> -	char *v = NULL;
> -	struct strbuf key = STRBUF_INIT;
> -	strbuf_addf(&key, "alias.%s", alias);
> -	if (git_config_key_is_valid(key.buf))
> -		git_config_get_string(key.buf, &v);
> -	strbuf_release(&key);
> -	return v;
> +	struct config_alias_data data = { STRBUF_INIT, NULL };
> +
> +	strbuf_addf(&data.key, "alias.%s", alias);
> +	if (git_config_key_is_valid(data.key.buf))
> +		read_early_config(config_alias_cb, &data);
> +	strbuf_release(&data.key);
> +
> +	return data.v;
>  }
>  
>  #define SPLIT_CMDLINE_BAD_ENDING 1
> diff --git a/git.c b/git.c
> index 8ff44f081..4e556fa9a 100644
> --- a/git.c
> +++ b/git.c
> @@ -16,50 +16,6 @@ const char git_more_info_string[] =
>  	   "to read about a specific subcommand or concept.");
>  
>  static int use_pager = -1;
> -static char *orig_cwd;
> -static const char *env_names[] = {
> -	GIT_DIR_ENVIRONMENT,
> -	GIT_WORK_TREE_ENVIRONMENT,
> -	GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
> -	GIT_PREFIX_ENVIRONMENT
> -};
> -static char *orig_env[4];
> -static int save_restore_env_balance;
> -
> -static void save_env_before_alias(void)
> -{
> -	int i;
> -
> -	assert(save_restore_env_balance == 0);
> -	save_restore_env_balance = 1;
> -	orig_cwd = xgetcwd();
> -	for (i = 0; i < ARRAY_SIZE(env_names); i++) {
> -		orig_env[i] = getenv(env_names[i]);
> -		orig_env[i] = xstrdup_or_null(orig_env[i]);
> -	}
> -}
> -
> -static void restore_env(int external_alias)
> -{
> -	int i;
> -
> -	assert(save_restore_env_balance == 1);
> -	save_restore_env_balance = 0;
> -	if (!external_alias && orig_cwd && chdir(orig_cwd))
> -		die_errno("could not move to %s", orig_cwd);
> -	free(orig_cwd);
> -	for (i = 0; i < ARRAY_SIZE(env_names); i++) {
> -		if (external_alias &&
> -		    !strcmp(env_names[i], GIT_PREFIX_ENVIRONMENT))
> -			continue;
> -		if (orig_env[i]) {
> -			setenv(env_names[i], orig_env[i], 1);
> -			free(orig_env[i]);
> -		} else {
> -			unsetenv(env_names[i]);
> -		}
> -	}
> -}
>  
>  static void commit_pager_choice(void) {
>  	switch (use_pager) {
> @@ -250,19 +206,17 @@ static int handle_alias(int *argcp, const char ***argv)
>  	const char **new_argv;
>  	const char *alias_command;
>  	char *alias_string;
> -	int unused_nongit;
> -
> -	save_env_before_alias();
> -	setup_git_directory_gently(&unused_nongit);
>  
>  	alias_command = (*argv)[0];
>  	alias_string = alias_lookup(alias_command);
>  	if (alias_string) {
>  		if (alias_string[0] == '!') {
> +			int nongit_ok;
>  			struct child_process child = CHILD_PROCESS_INIT;
>  
> +			setup_git_directory_gently(&nongit_ok);
> +
>  			commit_pager_choice();
> -			restore_env(1);
>  
>  			child.use_shell = 1;
>  			argv_array_push(&child.args, alias_string + 1);
> @@ -308,8 +262,6 @@ static int handle_alias(int *argcp, const char ***argv)
>  		ret = 1;
>  	}
>  
> -	restore_env(0);
> -
>  	errno = saved_errno;
>  
>  	return ret;
> diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
> index 83881ec3a..20b4d83c2 100755
> --- a/t/t7006-pager.sh
> +++ b/t/t7006-pager.sh
> @@ -391,7 +391,7 @@ test_expect_success TTY 'core.pager in repo config works and retains cwd' '
>  	)
>  '
>  
> -test_expect_failure TTY 'core.pager is found via alias in subdirectory' '
> +test_expect_success TTY 'core.pager is found via alias in subdirectory' '
>  	sane_unset GIT_PAGER &&
>  	test_config core.pager "cat >via-alias" &&
>  	(