config: add '--show-scope' to print the scope of a config value

When a user queries config values with --show-origin, often it's
difficult to determine what the actual "scope" (local, global, etc.) of
a given value is based on just the origin file.

Teach 'git config' the '--show-scope' option to print the scope of all
displayed config values.  Note that we should never see anything of
"submodule" scope as that is only ever used by submodule-config.c when
parsing the '.gitmodules' file.

Signed-off-by: Matthew Rogers <mattr94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-config.txt

@@ -9,18 +9,18 @@ git-config - Get and set repository or global options
 SYNOPSIS
 --------
 [verse]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] name [value [value_regex]]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] name [value [value_regex]]
 'git config' [<file-option>] [--type=<type>] --add name value
 'git config' [<file-option>] [--type=<type>] --replace-all name value [value_regex]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] --get name [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] --get name [value_regex]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] --get-all name [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] --get-all name [value_regex]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] [--name-only] --get-regexp name_regex [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--name-only] --get-regexp name_regex [value_regex]
 'git config' [<file-option>] [--type=<type>] [-z|--null] --get-urlmatch name URL
 'git config' [<file-option>] --unset name [value_regex]
 'git config' [<file-option>] --unset-all name [value_regex]
 'git config' [<file-option>] --rename-section old_name new_name
 'git config' [<file-option>] --remove-section name
-'git config' [<file-option>] [--show-origin] [-z|--null] [--name-only] -l | --list
+'git config' [<file-option>] [--show-origin] [--show-scope] [-z|--null] [--name-only] -l | --list
 'git config' [<file-option>] --get-color name [default]
 'git config' [<file-option>] --get-colorbool name [stdout-is-tty]
 'git config' [<file-option>] -e | --edit
@@ -222,6 +222,11 @@ Valid `<type>`'s include:
 	the actual origin (config file path, ref, or blob id if
 	applicable).
 
+--show-scope::
+	Similar to `--show-origin` in that it augments the output of
+	all queried config options with the scope of that value
+	(local, global, system, command).
+
 --get-colorbool name [stdout-is-tty]::
 
 	Find the color setting for `name` (e.g. `color.diff`) and output

builtin/config.c

@@ -33,6 +33,7 @@ static int end_nul;
 static int respect_includes_opt = -1;
 static struct config_options config_options;
 static int show_origin;
+static int show_scope;
 
 #define ACTION_GET (1<<0)
 #define ACTION_GET_ALL (1<<1)
@@ -155,6 +156,7 @@ static struct option builtin_config_options[] = {
 	OPT_BOOL(0, "name-only", &omit_values, N_("show variable names only")),
 	OPT_BOOL(0, "includes", &respect_includes_opt, N_("respect include directives on lookup")),
 	OPT_BOOL(0, "show-origin", &show_origin, N_("show origin of config (file, standard input, blob, command line)")),
+	OPT_BOOL(0, "show-scope", &show_scope, N_("show scope of config (worktree, local, global, system, command)")),
 	OPT_STRING(0, "default", &default_value, N_("value"), N_("with --get, use default value when missing entry")),
 	OPT_END(),
 };
@@ -189,10 +191,22 @@ static void show_config_origin(struct strbuf *buf)
 	strbuf_addch(buf, term);
 }
 
+static void show_config_scope(struct strbuf *buf)
+{
+	const char term = end_nul ? '\0' : '\t';
+	const char *scope = config_scope_name(current_config_scope());
+
+	strbuf_addstr(buf, N_(scope));
+	strbuf_addch(buf, term);
+}
+
 static int show_all_config(const char *key_, const char *value_, void *cb)
 {
-	if (show_origin) {
+	if (show_origin || show_scope) {
 		struct strbuf buf = STRBUF_INIT;
+		if (show_scope)
+			show_config_scope(&buf);
+		if (show_origin)
 			show_config_origin(&buf);
 		/* Use fwrite as "buf" can contain \0's if "end_null" is set. */
 		fwrite(buf.buf, 1, buf.len, stdout);
@@ -213,6 +227,8 @@ struct strbuf_list {
 
 static int format_config(struct strbuf *buf, const char *key_, const char *value_)
 {
+	if (show_scope)
+		show_config_scope(buf);
 	if (show_origin)
 		show_config_origin(buf);
 	if (show_keys)

t/t1300-config.sh

@@ -1771,6 +1771,65 @@ test_expect_success '--show-origin blob ref' '
 	test_cmp expect output
 '
 
+test_expect_success '--show-scope with --list' '
+	cat >expect <<-EOF &&
+	global	user.global=true
+	global	user.override=global
+	global	include.path=$INCLUDE_DIR/absolute.include
+	global	user.absolute=include
+	local	user.local=true
+	local	user.override=local
+	local	include.path=../include/relative.include
+	local	user.relative=include
+	command	user.cmdline=true
+	EOF
+	git -c user.cmdline=true config --list --show-scope >output &&
+	test_cmp expect output
+'
+
+test_expect_success !MINGW '--show-scope with --blob' '
+	blob=$(git hash-object -w "$CUSTOM_CONFIG_FILE") &&
+	cat >expect <<-EOF &&
+	command	user.custom=true
+	EOF
+	git config --blob=$blob --show-scope --list >output &&
+	test_cmp expect output
+'
+
+test_expect_success '--show-scope with --local' '
+	cat >expect <<-\EOF &&
+	local	user.local=true
+	local	user.override=local
+	local	include.path=../include/relative.include
+	EOF
+	git config --local --list --show-scope >output &&
+	test_cmp expect output
+'
+
+test_expect_success '--show-scope getting a single value' '
+	cat >expect <<-\EOF &&
+	local	true
+	EOF
+	git config --show-scope --get user.local >output &&
+	test_cmp expect output
+'
+
+test_expect_success '--show-scope with --show-origin' '
+	cat >expect <<-EOF &&
+	global	file:$HOME/.gitconfig	user.global=true
+	global	file:$HOME/.gitconfig	user.override=global
+	global	file:$HOME/.gitconfig	include.path=$INCLUDE_DIR/absolute.include
+	global	file:$INCLUDE_DIR/absolute.include	user.absolute=include
+	local	file:.git/config	user.local=true
+	local	file:.git/config	user.override=local
+	local	file:.git/config	include.path=../include/relative.include
+	local	file:.git/../include/relative.include	user.relative=include
+	command	command line:	user.cmdline=true
+	EOF
+	git -c user.cmdline=true config --list --show-origin --show-scope >output &&
+	test_cmp expect output
+'
+
 test_expect_success '--local requires a repo' '
 	# we expect 128 to ensure that we do not simply
 	# fail to find anything and return code "1"