completion: adapt git-config(1) to complete subcommands

With fe3ccc7aab (Merge branch 'ps/config-subcommands', 2024-05-15),
git-config(1) has gained support for subcommands. These subcommands live
next to the old, action-based mode, so that both the old and new way
continue to work.

The manpage for this command has been updated to prominently show the
subcommands, and the action-based modes are marked as deprecated. Update
Bash completion scripts accordingly to advertise subcommands instead of
actions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -2989,22 +2989,42 @@ __git_complete_config_variable_name_and_value ()
 
 _git_config ()
 {
-	case "$prev" in
+	local subcommands subcommand
-	--get|--get-all|--unset|--unset-all)
+
-		__gitcomp_nl "$(__git_config_get_set_variables)"
+	__git_resolve_builtins "config"
+
+	subcommands="$___git_resolved_builtins"
+	subcommand="$(__git_find_subcommand "$subcommands")"
+
+	if [ -z "$subcommand" ]
+	then
+		__gitcomp "$subcommands"
 		return
-		;;
+	fi
-	*.*)
+
-		__git_complete_config_variable_value
+	case "$cur" in
+	--*)
+		__gitcomp_builtin "config_$subcommand"
 		return
 		;;
 	esac
-	case "$cur" in
+
-	--*)
+	case "$subcommand" in
-		__gitcomp_builtin config
+	get)
+		__gitcomp_nl "$(__git_config_get_set_variables)"
 		;;
-	*)
+	set)
-		__git_complete_config_variable_name
+		case "$prev" in
+		*.*)
+			__git_complete_config_variable_value
+			;;
+		*)
+			__git_complete_config_variable_name
+			;;
+		esac
+		;;
+	unset)
+		__gitcomp_nl "$(__git_config_get_set_variables)"
 		;;
 	esac
 }

t/t9902-completion.sh

@@ -2742,30 +2742,58 @@ do
 	'
 done
 
-test_expect_success 'git config - section' '
+test_expect_success 'git config subcommand' '
-	test_completion "git config br" <<-\EOF
+	test_completion "git config " <<-\EOF
+	edit Z
+	get Z
+	list Z
+	remove-section Z
+	rename-section Z
+	set Z
+	unset Z
+	EOF
+'
+
+test_expect_success 'git config subcommand options' '
+	test_completion "git config get --show-" <<-\EOF
+	--show-names Z
+	--show-origin Z
+	--show-scope Z
+	EOF
+'
+
+test_expect_success 'git config get' '
+	test_when_finished "rm -f cfgfile" &&
+	git config set --file cfgfile foo.bar baz &&
+	test_completion "git config get --file cfgfile foo." <<-\EOF
+	foo.bar Z
+	EOF
+'
+
+test_expect_success 'git config set - section' '
+	test_completion "git config set br" <<-\EOF
 	branch.Z
 	browser.Z
 	EOF
 '
 
-test_expect_success 'git config - section include, includeIf' '
+test_expect_success 'git config set - section include, includeIf' '
-	test_completion "git config inclu" <<-\EOF
+	test_completion "git config set inclu" <<-\EOF
 	include.Z
 	includeIf.Z
 	EOF
 '
 
-test_expect_success 'git config - variable name' '
+test_expect_success 'git config set - variable name' '
-	test_completion "git config log.d" <<-\EOF
+	test_completion "git config set log.d" <<-\EOF
 	log.date Z
 	log.decorate Z
 	log.diffMerges Z
 	EOF
 '
 
-test_expect_success 'git config - variable name include' '
+test_expect_success 'git config set - variable name include' '
-	test_completion "git config include.p" <<-\EOF
+	test_completion "git config set include.p" <<-\EOF
 	include.path Z
 	EOF
 '
@@ -2776,8 +2804,8 @@ test_expect_success 'setup for git config submodule tests' '
 	git submodule add ./sub
 '
 
-test_expect_success 'git config - variable name - submodule and __git_compute_first_level_config_vars_for_section' '
+test_expect_success 'git config set - variable name - submodule and __git_compute_first_level_config_vars_for_section' '
-	test_completion "git config submodule." <<-\EOF
+	test_completion "git config set submodule." <<-\EOF
 	submodule.active Z
 	submodule.alternateErrorStrategy Z
 	submodule.alternateLocation Z
@@ -2788,8 +2816,8 @@ test_expect_success 'git config - variable name - submodule and __git_compute_fi
 	EOF
 '
 
-test_expect_success 'git config - variable name - __git_compute_second_level_config_vars_for_section' '
+test_expect_success 'git config set - variable name - __git_compute_second_level_config_vars_for_section' '
-	test_completion "git config submodule.sub." <<-\EOF
+	test_completion "git config set submodule.sub." <<-\EOF
 	submodule.sub.url Z
 	submodule.sub.update Z
 	submodule.sub.branch Z
@@ -2799,8 +2827,8 @@ test_expect_success 'git config - variable name - __git_compute_second_level_con
 	EOF
 '
 
-test_expect_success 'git config - value' '
+test_expect_success 'git config set - value' '
-	test_completion "git config color.pager " <<-\EOF
+	test_completion "git config set color.pager " <<-\EOF
 	false Z
 	true Z
 	EOF