Re: Tiny bug report, interaction between alias and help

[Jeff King <peff@peff.net>]

On Sat, Jan 19, 2008 at 09:27:50AM -0500, François Pinard wrote:

> Page http://git.or.cz/#community says to report git bugs on this list.
> This is a tiny bug for "git version 1.5.4.rc3.14.g44397-dirty".  If the
> "bug" is inappropriate, please then consider this as a suggestion!  :-)

I think it is more of a feature request than a bug, and as such should
probably be dealt with post-1.5.4.

> If, after "git config --global alias.st status", say, I try:
>
>   git st --help
>
> git then replies:
>
>   No manual entry for git-st
>
> It would be nice if --help was interacting better with aliases.

Maybe something like the following would be nicer. It would be a lot
cleaner if the parsing were done by parseopt (which is hopefully going
to happen post-1.5.4).

-- >8 --
help: print alias definitions

When asking for "git help alias", we unhelpfully just
tried to look for the manpage for "git-alias" which almost
certainly doesn't exist. Instead, let's print out the alias
definition.
---
 help.c |   43 ++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/help.c b/help.c
index 1302a61..35176eb 100644
--- a/help.c
+++ b/help.c
@@ -334,6 +334,27 @@ static void show_html_page(const char *git_cmd)
 	execl_git_cmd("help--browse", page, NULL);
 }
 
+static const char *alias_help_cb_key;
+static char *alias_help_cb_value;
+static int alias_help_cb(const char *k, const char *v)
+{
+	if (!prefixcmp(k, "alias.") && !strcmp(k+6, alias_help_cb_key))
+		alias_help_cb_value = xstrdup(v);
+	return 0;
+}
+
+static int show_alias_help(const char *git_cmd)
+{
+	alias_help_cb_key = git_cmd;
+	alias_help_cb_value = NULL;
+	git_config(alias_help_cb);
+	if (!alias_help_cb_value)
+		return 0;
+	printf("`git %s' is aliased to `%s'\n", git_cmd, alias_help_cb_value);
+	free(alias_help_cb_value);
+	return 1;
+}
+
 void help_unknown_cmd(const char *cmd)
 {
 	fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
@@ -349,6 +370,9 @@ int cmd_version(int argc, const char **argv, const char *prefix)
 int cmd_help(int argc, const char **argv, const char *prefix)
 {
 	const char *help_cmd = argv[1];
+	int nongit;
+
+	setup_git_directory_gently(&nongit);
 
 	if (argc < 2) {
 		printf("usage: %s\n\n", git_usage_string);
@@ -362,21 +386,30 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	}
 
 	else if (!strcmp(help_cmd, "--web") || !strcmp(help_cmd, "-w")) {
-		show_html_page(argc > 2 ? argv[2] : NULL);
+		const char *cmd = argc > 2 ? argv[2] : NULL;
+		if (cmd && show_alias_help(cmd))
+			return 0;
+		show_html_page(cmd);
 	}
 
 	else if (!strcmp(help_cmd, "--info") || !strcmp(help_cmd, "-i")) {
-		show_info_page(argc > 2 ? argv[2] : NULL);
+		const char *cmd = argc > 2 ? argv[2] : NULL;
+		if (cmd && show_alias_help(cmd))
+			return 0;
+		show_info_page(cmd);
 	}
 
 	else if (!strcmp(help_cmd, "--man") || !strcmp(help_cmd, "-m")) {
-		show_man_page(argc > 2 ? argv[2] : NULL);
+		const char *cmd = argc > 2 ? argv[2] : NULL;
+		if (cmd && show_alias_help(cmd))
+			return 0;
+		show_man_page(cmd);
 	}
 
 	else {
-		int nongit;
+		if (show_alias_help(help_cmd))
+			return 0;
 
-		setup_git_directory_gently(&nongit);
 		git_config(git_help_config);
 		if (help_default_format)
 			parse_help_format(help_default_format);
-- 
1.5.4.rc3.1129.g3e1ca-dirty