mailinfo: read local configuration

Since b9605bc4f2 ("config: only read .git/config from configured
repos", 2016-09-12), we do not read from ".git/config" unless we
know we are in a repository.  "git mailinfo" however didn't do the
repository discovery and instead relied on the old behaviour.  This
was mostly OK because it was merely run as a helper program by other
porcelain scripts that first chdir's up to the root of the working
tree.

Teach the command to run a "gentle" version of repository discovery
so that local configuration variables like mailinfo.scissors are
honoured.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/mailinfo.c

@@ -11,15 +11,20 @@
 static const char mailinfo_usage[] =
 	"git mailinfo [-k | -b] [-m | --message-id] [-u | --encoding=<encoding> | -n] [--scissors | --no-scissors] <msg> <patch> < mail >info";
 
+static char *prefix_copy(const char *prefix, const char *filename)
+{
+	if (!prefix || is_absolute_path(filename))
+		return xstrdup(filename);
+	return xstrdup(prefix_filename(prefix, strlen(prefix), filename));
+}
+
 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 {
 	const char *def_charset;
 	struct mailinfo mi;
 	int status;
+	char *msgfile, *patchfile;
 
-	/* NEEDSWORK: might want to do the optional .git/ directory
-	 * discovery
-	 */
 	setup_mailinfo(&mi);
 
 	def_charset = get_commit_output_encoding();
@@ -54,8 +59,14 @@ int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 
 	mi.input = stdin;
 	mi.output = stdout;
-	status = !!mailinfo(&mi, argv[1], argv[2]);
+
+	msgfile = prefix_copy(prefix, argv[1]);
+	patchfile = prefix_copy(prefix, argv[2]);
+
+	status = !!mailinfo(&mi, msgfile, patchfile);
 	clear_mailinfo(&mi);
 
+	free(msgfile);
+	free(patchfile);
 	return status;
 }

git.c

@@ -445,7 +445,7 @@ static struct cmd_struct commands[] = {
 	{ "ls-files", cmd_ls_files, RUN_SETUP | SUPPORT_SUPER_PREFIX },
 	{ "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 	{ "ls-tree", cmd_ls_tree, RUN_SETUP },
-	{ "mailinfo", cmd_mailinfo },
+	{ "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 	{ "mailsplit", cmd_mailsplit },
 	{ "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 	{ "merge-base", cmd_merge_base, RUN_SETUP },

t/t5100-mailinfo.sh

@@ -158,4 +158,17 @@ test_expect_success 'mailinfo handles rfc2822 comment' '
 	test_cmp "$DATA/comment.expect" comment/info
 '
 
+test_expect_success 'mailinfo with mailinfo.scissors config' '
+	test_config mailinfo.scissors true &&
+	(
+		mkdir sub &&
+		cd sub &&
+		git mailinfo ../msg0014.sc ../patch0014.sc <../0014 >../info0014.sc
+	) &&
+	test_cmp "$DATA/msg0014--scissors" msg0014.sc &&
+	test_cmp "$DATA/patch0014--scissors" patch0014.sc &&
+	test_cmp "$DATA/info0014--scissors" info0014.sc
+'
+
+
 test_done