Merge branch 'dl/stash-show-untracked'

"git stash show" learned to optionally show untracked part of the
stash.

* dl/stash-show-untracked:
  stash show: learn stash.showIncludeUntracked
  stash show: teach --include-untracked and --only-untracked

7 files changed, 214 insertions, 9 deletions

diff --git a/Documentation/config/stash.txt b/Documentation/config/stash.txt
index 00eb35434e..413f907cba 100644
--- a/Documentation/config/stash.txt
+++ b/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.
diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
index f1197d641b..a8c8c32f1e 100644
--- a/Documentation/git-stash.txt
+++ b/Documentation/git-stash.txt
@@ -9,7 +9,7 @@ SYNOPSIS
 --------
 [verse]
 'git stash' list [<log-options>]
-'git stash' show [<diff-options>] [<stash>]
+'git stash' show [-u|--include-untracked|--only-untracked] [<diff-options>] [<stash>]
 'git stash' drop [-q|--quiet] [<stash>]
 'git stash' ( pop | apply ) [--index] [-q|--quiet] [<stash>]
 'git stash' branch <branchname> [<stash>]
@@ -83,7 +83,7 @@ stash@{1}: On master: 9cc0589... Add git-stash
 The command takes options applicable to the 'git log'
 command to control what is shown and how. See linkgit:git-log[1].
 
-show [<diff-options>] [<stash>]::
+show [-u|--include-untracked|--only-untracked] [<diff-options>] [<stash>]::
 
 	Show the changes recorded in the stash entry as a diff between the
 	stashed contents and the commit back when the stash entry was first
@@ -91,8 +91,8 @@ show [<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
-	to change the default behavior.
+	You can use stash.showIncludeUntracked, stash.showStat, and
+	stash.showPatch config variables to change the default behavior.
 
 pop [--index] [-q|--quiet] [<stash>]::
 
@@ -160,10 +160,18 @@ up with `git clean`.
 
 -u::
 --include-untracked::
-	This option is only valid for `push` and `save` commands.
+--no-include-untracked::
+	When used with the `push` and `save` commands,
+	all untracked files are also stashed and then cleaned up with
+	`git clean`.
++
+When used with the `show` command, show the untracked files in the stash
+entry as part of the diff.
+
+--only-untracked::
+	This option is only valid for the `show` command.
 +
-All untracked files are also stashed and then cleaned up with
-`git clean`.
+Show only the untracked files in the stash entry as part of the diff.
 
 --index::
 	This option is only valid for `pop` and `apply` commands.
diff --git a/builtin/stash.c b/builtin/stash.c
index ba774cce67..3477e940e3 100644
--- a/builtin/stash.c
+++ b/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;
@@ -787,6 +792,33 @@ static int git_stash_config(const char *var, const char *value, void *cb)
 	return git_diff_basic_config(var, value, cb);
 }
 
+static void diff_include_untracked(const struct stash_info *info, struct diff_options *diff_opt)
+{
+	const struct object_id *oid[] = { &info->w_commit, &info->u_tree };
+	struct tree *tree[ARRAY_SIZE(oid)];
+	struct tree_desc tree_desc[ARRAY_SIZE(oid)];
+	struct unpack_trees_options unpack_tree_opt = { 0 };
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(oid); i++) {
+		tree[i] = parse_tree_indirect(oid[i]);
+		if (parse_tree(tree[i]) < 0)
+			die(_("failed to parse tree"));
+		init_tree_desc(&tree_desc[i], tree[i]->buffer, tree[i]->size);
+	}
+
+	unpack_tree_opt.head_idx = -1;
+	unpack_tree_opt.src_index = &the_index;
+	unpack_tree_opt.dst_index = &the_index;
+	unpack_tree_opt.merge = 1;
+	unpack_tree_opt.fn = stash_worktree_untracked_merge;
+
+	if (unpack_trees(ARRAY_SIZE(tree_desc), tree_desc, &unpack_tree_opt))
+		die(_("failed to unpack trees"));
+
+	do_diff_cache(&info->b_commit, diff_opt);
+}
+
 static int show_stash(int argc, const char **argv, const char *prefix)
 {
 	int i;
@@ -795,7 +827,18 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	struct rev_info rev;
 	struct strvec stash_args = STRVEC_INIT;
 	struct strvec revision_args = STRVEC_INIT;
+	enum {
+		UNTRACKED_NONE,
+		UNTRACKED_INCLUDE,
+		UNTRACKED_ONLY
+	} show_untracked = UNTRACKED_NONE;
 	struct option options[] = {
+		OPT_SET_INT('u', "include-untracked", &show_untracked,
+			    N_("include untracked files in the stash"),
+			    UNTRACKED_INCLUDE),
+		OPT_SET_INT_F(0, "only-untracked", &show_untracked,
+			      N_("only show untracked files in the stash"),
+			      UNTRACKED_ONLY, PARSE_OPT_NONEG),
 		OPT_END()
 	};
 
@@ -803,6 +846,10 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	git_config(git_diff_ui_config, NULL);
 	init_revisions(&rev, prefix);
 
+	argc = parse_options(argc, argv, prefix, options, git_stash_show_usage,
+			     PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
+			     PARSE_OPT_KEEP_DASHDASH);
+
 	strvec_push(&revision_args, argv[0]);
 	for (i = 1; i < argc; i++) {
 		if (argv[i][0] != '-')
@@ -827,6 +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;
@@ -845,7 +895,17 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 
 	rev.diffopt.flags.recursive = 1;
 	setup_diff_pager(&rev.diffopt);
-	diff_tree_oid(&info.b_commit, &info.w_commit, "", &rev.diffopt);
+	switch (show_untracked) {
+	case UNTRACKED_NONE:
+		diff_tree_oid(&info.b_commit, &info.w_commit, "", &rev.diffopt);
+		break;
+	case UNTRACKED_ONLY:
+		diff_root_tree_oid(&info.u_tree, "", &rev.diffopt);
+		break;
+	case UNTRACKED_INCLUDE:
+		diff_include_untracked(&info, &rev.diffopt);
+		break;
+	}
 	log_tree_diff_flush(&rev);
 
 	free_stash_info(&info);
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 7dc6cd8eb8..e1a66954fe 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -3053,7 +3053,7 @@ _git_stash ()
 			__gitcomp "--name-status --oneline --patch-with-stat"
 			;;
 		show,--*)
-			__gitcomp "$__git_diff_common_options"
+			__gitcomp "--include-untracked --only-untracked $__git_diff_common_options"
 			;;
 		branch,--*)
 			;;
diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
index 598b17f6d4..8314ab21d4 100755
--- a/t/t3905-stash-include-untracked.sh
+++ b/t/t3905-stash-include-untracked.sh
@@ -297,4 +297,112 @@ test_expect_success 'stash -u with globs' '
 	test_path_is_missing untracked.txt
 '
 
+test_expect_success 'stash show --include-untracked shows untracked files' '
+	git reset --hard &&
+	git clean -xf &&
+	>untracked &&
+	>tracked &&
+	git add tracked &&
+	empty_blob_oid=$(git rev-parse --short :tracked) &&
+	git stash -u &&
+
+	cat >expect <<-EOF &&
+	 tracked   | 0
+	 untracked | 0
+	 2 files changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git stash show --include-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show -u >actual &&
+	test_cmp expect actual &&
+	git stash show --no-include-untracked --include-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show --only-untracked --include-untracked >actual &&
+	test_cmp expect actual &&
+	git -c stash.showIncludeUntracked=true stash show >actual &&
+	test_cmp expect actual &&
+
+	cat >expect <<-EOF &&
+	diff --git a/tracked b/tracked
+	new file mode 100644
+	index 0000000..$empty_blob_oid
+	diff --git a/untracked b/untracked
+	new file mode 100644
+	index 0000000..$empty_blob_oid
+	EOF
+	git stash show -p --include-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show --include-untracked -p >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash show --only-untracked only shows untracked files' '
+	git reset --hard &&
+	git clean -xf &&
+	>untracked &&
+	>tracked &&
+	git add tracked &&
+	empty_blob_oid=$(git rev-parse --short :tracked) &&
+	git stash -u &&
+
+	cat >expect <<-EOF &&
+	 untracked | 0
+	 1 file changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git stash show --only-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show --no-include-untracked --only-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show --include-untracked --only-untracked >actual &&
+	test_cmp expect actual &&
+
+	cat >expect <<-EOF &&
+	diff --git a/untracked b/untracked
+	new file mode 100644
+	index 0000000..$empty_blob_oid
+	EOF
+	git stash show -p --only-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show --only-untracked -p >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash show --no-include-untracked cancels --{include,show}-untracked' '
+	git reset --hard &&
+	git clean -xf &&
+	>untracked &&
+	>tracked &&
+	git add tracked &&
+	git stash -u &&
+
+	cat >expect <<-EOF &&
+	 tracked | 0
+	 1 file changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git stash show --only-untracked --no-include-untracked >actual &&
+	test_cmp expect actual &&
+	git stash show --include-untracked --no-include-untracked >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash show --include-untracked errors on duplicate files' '
+	git reset --hard &&
+	git clean -xf &&
+	>tracked &&
+	git add tracked &&
+	tree=$(git write-tree) &&
+	i_commit=$(git commit-tree -p HEAD -m "index on any-branch" "$tree") &&
+	test_when_finished "rm -f untracked_index" &&
+	u_commit=$(
+		GIT_INDEX_FILE="untracked_index" &&
+		export GIT_INDEX_FILE &&
+		git update-index --add tracked &&
+		u_tree=$(git write-tree) &&
+		git commit-tree -m "untracked files on any-branch" "$u_tree"
+	) &&
+	w_commit=$(git commit-tree -p HEAD -p "$i_commit" -p "$u_commit" -m "WIP on any-branch" "$tree") &&
+	test_must_fail git stash show --include-untracked "$w_commit" 2>err &&
+	test_i18ngrep "worktree and untracked commit have duplicate entries: tracked" err
+'
+
 test_done
diff --git a/unpack-trees.c b/unpack-trees.c
index 9298fe1d9b..9af8e796b3 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -2563,3 +2563,25 @@ int oneway_merge(const struct cache_entry * const *src,
 	}
 	return merged_entry(a, old, o);
 }
+
+/*
+ * Merge worktree and untracked entries in a stash entry.
+ *
+ * Ignore all index entries. Collapse remaining trees but make sure that they
+ * don't have any conflicting files.
+ */
+int stash_worktree_untracked_merge(const struct cache_entry * const *src,
+				   struct unpack_trees_options *o)
+{
+	const struct cache_entry *worktree = src[1];
+	const struct cache_entry *untracked = src[2];
+
+	if (o->merge_size != 2)
+		BUG("invalid merge_size: %d", o->merge_size);
+
+	if (worktree && untracked)
+		return error(_("worktree and untracked commit have duplicate entries: %s"),
+			     super_prefixed(worktree->name));
+
+	return merged_entry(worktree ? worktree : untracked, NULL, o);
+}
diff --git a/unpack-trees.h b/unpack-trees.h
index 2e87875b15..2d88b19dca 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -114,5 +114,7 @@ int bind_merge(const struct cache_entry * const *src,
 	       struct unpack_trees_options *o);
 int oneway_merge(const struct cache_entry * const *src,
 		 struct unpack_trees_options *o);
+int stash_worktree_untracked_merge(const struct cache_entry * const *src,
+				   struct unpack_trees_options *o);
 
 #endif