shortlog: run setup_git_directory_gently() sooner

shortlog already runs a repository search unconditionally;
running such a search earlier is not very risky.

Without this change, the “[pager] shortlog” configuration
is not respected at all: “git shortlog” unconditionally paginates.

The tests are a bit slow.  Running the full battery like this
for all built-in commands would be counterproductive; the intent is
rather to test shortlog as a representative example command using
..._gently().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/shortlog.c

@@ -249,7 +249,7 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 {
 	static struct shortlog log;
 	static struct rev_info rev;
-	int nongit;
+	int nongit = !startup_info->have_repository;
 
 	static const struct option options[] = {
 		OPT_BOOLEAN('n', "numbered", &log.sort_by_number,
@@ -265,7 +265,6 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 
 	struct parse_opt_ctx_t ctx;
 
-	prefix = setup_git_directory_gently(&nongit);
 	git_config(git_default_config, NULL);
 	shortlog_init(&log);
 	init_revisions(&rev, prefix);

git.c

@@ -384,7 +384,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 		{ "rm", cmd_rm, RUN_SETUP },
 		{ "send-pack", cmd_send_pack, RUN_SETUP },
-		{ "shortlog", cmd_shortlog, USE_PAGER },
+		{ "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 		{ "show-branch", cmd_show_branch, RUN_SETUP },
 		{ "show", cmd_show, RUN_SETUP | USE_PAGER },
 		{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },

t/t7006-pager.sh

@@ -369,4 +369,13 @@ test_GIT_PAGER_overrides  expect_success test_must_fail 'git -p'
 
 test_doesnt_paginate      expect_failure test_must_fail 'git -p nonsense'
 
+test_pager_choices                       'git shortlog'
+test_expect_success 'setup: configure shortlog not to paginate' '
+	git config pager.shortlog false
+'
+test_doesnt_paginate      expect_success 'git shortlog'
+test_no_local_config_subdir expect_success 'git shortlog'
+test_default_pager        expect_success 'git -p shortlog'
+test_core_pager_subdir    expect_success 'git -p shortlog'
+
 test_done