[PATCH v2 16/17] ls: do not show duplicate cached entries

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

With the current show_files() "ls -tcm" will show

  foo.c
M foo.c

The first item is redundant. If "foo.c" is modified, we know it's in
the cache. Introduce show_files_compact to do that because ls-files is
plumbing and scripts may already depend on current display behavior.

Another difference in show_files_compact() is it does not show
skip-worktree (aka outside sparse checkout) entries anymore, which
makes sense in porcelain context.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 builtin/ls-files.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 709d8b1..cd8e35c 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -337,6 +337,53 @@ static void show_files(struct dir_struct *dir)
 	}
 }
 
+static void show_files_compact(struct dir_struct *dir)
+{
+	int i;
+
+	/* For cached/deleted files we don't need to even do the readdir */
+	if (show_others || show_killed) {
+		if (!show_others)
+			dir->flags |= DIR_COLLECT_KILLED_ONLY;
+		fill_directory(dir, &pathspec);
+		if (show_others)
+			show_other_files(dir);
+		if (show_killed)
+			show_killed_files(dir);
+	}
+	if (!(show_cached || show_stage || show_deleted || show_modified))
+		return;
+	for (i = 0; i < active_nr; i++) {
+		const struct cache_entry *ce = active_cache[i];
+		struct stat st;
+		int err, shown = 0;
+		if ((dir->flags & DIR_SHOW_IGNORED) &&
+		    !ce_excluded(dir, ce))
+			continue;
+		if (show_unmerged && !ce_stage(ce))
+			continue;
+		if (ce->ce_flags & CE_UPDATE)
+			continue;
+		if (ce_skip_worktree(ce))
+			continue;
+		err = lstat(ce->name, &st);
+		if (show_deleted && err) {
+			show_ce_entry(tag_removed, ce);
+			shown = 1;
+		}
+		if (show_modified && ce_modified(ce, &st, 0)) {
+			show_ce_entry(tag_modified, ce);
+			shown = 1;
+		}
+		if (ce_stage(ce)) {
+			show_ce_entry(tag_unmerged, ce);
+			shown = 1;
+		}
+		if (!shown && show_cached)
+			show_ce_entry(tag_cached, ce);
+	}
+}
+
 /*
  * Prune the index to only contain stuff starting with "prefix"
  */
@@ -606,7 +653,10 @@ static int ls_files(const char **argv, const char *prefix)
 		refresh_index(&the_index, REFRESH_QUIET, &pathspec, NULL, NULL);
 		setup_pager();
 	}
-	show_files(&dir);
+	if (porcelain)
+		show_files_compact(&dir);
+	else
+		show_files(&dir);
 	if (show_resolve_undo)
 		show_ru_info();
 
-- 
1.9.1.345.ga1a145c