[PATCH 16/16] ls-files: add --overlay option

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Narrow checkout mode introduces an interesting case: some files
are not to be checked out (marked CE_NO_CHECKOUT in index) but still
exist in working directory. Those files will be ignored by Git unless
explicitly specified. In Clearcase, these files are called "eclipsed".
I would call them "overlay" for now. Any better term is welcome.

The same situation happens for "assume unchanged" bit, but I would
expect narrow checkout to be more user-friendly and should notify users
these cases so users will not be confused. On this first step, users
may check by themselves with "git ls-files --overlay", further steps
may make the information visible from "git status".

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/git-ls-files.txt |    4 ++++
 builtin-ls-files.c             |   16 +++++++++++++---
 t/t2104-update-index-narrow.sh |    4 ++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-ls-files.txt b/Documentation/git-ls-files.txt
index 4f5a37e..9e749ef 100644
--- a/Documentation/git-ls-files.txt
+++ b/Documentation/git-ls-files.txt
@@ -56,6 +56,9 @@ OPTIONS
 --stage::
 	Show staged contents' object name, mode bits and stage number in the output.
 
+--overlay::
+	Show files that are marked no-checkout but exist in working directory.
+
 --directory::
 	If a whole directory is classified as "other", show just its
 	name (with a trailing slash) and not its whole contents.
@@ -122,6 +125,7 @@ OPTIONS
 	R::	removed/deleted
 	C::	modified/changed
 	K::	to be killed
+	!::	overlay files
 	?::	other
 
 -v::
diff --git a/builtin-ls-files.c b/builtin-ls-files.c
index f48a157..6e55207 100644
--- a/builtin-ls-files.c
+++ b/builtin-ls-files.c
@@ -20,6 +20,7 @@ static int show_others;
 static int show_stage;
 static int show_unmerged;
 static int show_modified;
+static int show_overlay;
 static int show_killed;
 static int show_valid_bit;
 static int narrow_checkout;
@@ -39,6 +40,7 @@ static const char *tag_removed = "";
 static const char *tag_other = "";
 static const char *tag_killed = "";
 static const char *tag_modified = "";
+static const char *tag_overlay = "";
 
 
 /*
@@ -256,7 +258,7 @@ static void show_files(struct dir_struct *dir, const char *prefix)
 			show_ce_entry(ce_stage(ce) ? tag_unmerged : tag_cached, ce);
 		}
 	}
-	if (show_deleted | show_modified) {
+	if (show_deleted | show_modified | show_overlay) {
 		for (i = 0; i < active_nr; i++) {
 			struct cache_entry *ce = active_cache[i];
 			struct stat st;
@@ -265,6 +267,8 @@ static void show_files(struct dir_struct *dir, const char *prefix)
 			if (excluded(dir, ce->name, &dtype) != dir->show_ignored)
 				continue;
 			err = lstat(ce->name, &st);
+			if (show_overlay && ce_no_checkout(ce) && !err)
+				show_ce_entry(tag_overlay, ce);
 			if (show_deleted && err && ce_checkout(ce))
 				show_ce_entry(tag_removed, ce);
 			if (show_modified && ce_modified(ce, &st, 0))
@@ -431,7 +435,7 @@ int report_path_error(const char *ps_matched, const char **pathspec, int prefix_
 }
 
 static const char ls_files_usage[] =
-	"git ls-files [-z] [-t] [-v] (--[cached|deleted|others|stage|unmerged|killed|modified])* "
+	"git ls-files [-z] [-t] [-v] (--[cached|deleted|others|stage|unmerged|killed|modified|overlay])* "
 	"[ --narrow-checkout ] [--narrow-match=<narrow_spec>] "
 	"[ --ignored ] [--exclude=<pattern>] [--exclude-from=<file>] "
 	"[ --exclude-per-directory=<filename> ] [--exclude-standard] "
@@ -466,6 +470,7 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 			tag_modified = "C ";
 			tag_other = "? ";
 			tag_killed = "K ";
+			tag_overlay = "! ";
 			if (arg[1] == 'v')
 				show_valid_bit = 1;
 			continue;
@@ -491,6 +496,11 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 			require_work_tree = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--overlay")) {
+			show_overlay = 1;
+			require_work_tree = 1;
+			continue;
+		}
 		if (!strcmp(arg, "-o") || !strcmp(arg, "--others")) {
 			show_others = 1;
 			require_work_tree = 1;
@@ -610,7 +620,7 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 
 	/* With no flags, we default to showing the cached files */
 	if (!(show_stage | show_deleted | show_others | show_unmerged |
-	      show_killed | show_modified))
+	      show_killed | show_modified | show_overlay))
 		show_cached = 1;
 
 	if (narrow_checkout && !show_cached && !show_stage)
diff --git a/t/t2104-update-index-narrow.sh b/t/t2104-update-index-narrow.sh
index 1a3acdd..79da418 100755
--- a/t/t2104-update-index-narrow.sh
+++ b/t/t2104-update-index-narrow.sh
@@ -31,6 +31,10 @@ test_expect_success 'ls-files --deleted ignores no-checkout entries' '
 	touch 1
 '
 
+test_expect_success 'there are overlay entries' '
+	test "$(git ls-files --overlay|grep 1|wc -l)" = 2
+'
+
 test_expect_success 'update-index --checkout' '
 	git update-index --checkout 1 sub/1 &&
 	test "$(git ls-files)" = "$(git ls-files --narrow-checkout)"'
-- 
1.6.0.96.g2fad1.dirty