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

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

@@ -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>]
@@ -83,16 +83,16 @@ 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
 	created.
 	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.

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)
@@ -780,13 +781,44 @@ 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;
 	}
 	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;
@@ -795,14 +827,29 @@ 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()
 	};
 
 	init_diff_ui_defaults();
 	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);

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,--*)
 			;;

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

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);
+}

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