stash show: learn stash.showIncludeUntracked

The previous commit teaches `git stash show --include-untracked`. It
may be desirable for a user to be able to always enable the
--include-untracked behavior. Teach the stash.showIncludeUntracked
config option which allows users to do this in a similar manner to
stash.showPatch.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config/stash.txt

@@ -5,6 +5,11 @@ stash.useBuiltin::
 	is always used. Setting this will emit a warning, to alert any
 	remaining users that setting this now does nothing.
 
+stash.showIncludeUntracked::
+	If this is set to true, the `git stash show` command without an
+	option will show the untracked files of a stash entry.  Defaults to
+	false. See description of 'show' command in linkgit:git-stash[1].
+
 stash.showPatch::
 	If this is set to true, the `git stash show` command without an
 	option will show the stash entry in patch form.  Defaults to false.

Documentation/git-stash.txt

@@ -91,8 +91,8 @@ show [-u|--include-untracked|--only-untracked] [<diff-options>] [<stash>]::
 	By default, the command shows the diffstat, but it will accept any
 	format known to 'git diff' (e.g., `git stash show -p stash@{1}`
 	to view the second most recent entry in patch form).
-	You can use stash.showStat and/or stash.showPatch config variables
+	You can use stash.showIncludeUntracked, stash.showStat, and
-	to change the default behavior.
+	stash.showPatch config variables to change the default behavior.
 
 pop [--index] [-q|--quiet] [<stash>]::
 

builtin/stash.c

@@ -768,6 +768,7 @@ static int list_stash(int argc, const char **argv, const char *prefix)
 
 static int show_stat = 1;
 static int show_patch;
+static int show_include_untracked;
 static int use_legacy_stash;
 
 static int git_stash_config(const char *var, const char *value, void *cb)
@@ -780,6 +781,10 @@ static int git_stash_config(const char *var, const char *value, void *cb)
 		show_patch = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "stash.showincludeuntracked")) {
+		show_include_untracked = git_config_bool(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "stash.usebuiltin")) {
 		use_legacy_stash = !git_config_bool(var, value);
 		return 0;
@@ -869,6 +874,9 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 		if (show_patch)
 			rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
 
+		if (show_include_untracked)
+			show_untracked = UNTRACKED_INCLUDE;
+
 		if (!show_stat && !show_patch) {
 			free_stash_info(&info);
 			return 0;

t/t3905-stash-include-untracked.sh

@@ -319,6 +319,8 @@ test_expect_success 'stash show --include-untracked shows untracked files' '
 	test_cmp expect actual &&
 	git stash show --only-untracked --include-untracked >actual &&
 	test_cmp expect actual &&
+	git -c stash.showIncludeUntracked=true stash show >actual &&
+	test_cmp expect actual &&
 
 	cat >expect <<-EOF &&
 	diff --git a/tracked b/tracked