[PATCH v2 09/19] ls-files.c: use index api

[Thomas Gummerer <t.gummerer@gmail.com>]

Use the index api to read only part of the index, if the on-disk version
of the index is index-v5.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
---
 builtin/ls-files.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 08d9786..80cc398 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -31,6 +31,7 @@ static const char *prefix;
 static int max_prefix_len;
 static int prefix_len;
 static const char **pathspec;
+static struct pathspec pathspec_struct;
 static int error_unmatch;
 static char *ps_matched;
 static const char *with_tree;
@@ -457,6 +458,7 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 	struct dir_struct dir;
 	struct exclude_list *el;
 	struct string_list exclude_list = STRING_LIST_INIT_NODUP;
+	struct filter_opts *opts = xmalloc(sizeof(*opts));
 	struct option builtin_ls_files_options[] = {
 		{ OPTION_CALLBACK, 'z', NULL, NULL, NULL,
 			N_("paths are separated with NUL character"),
@@ -522,9 +524,6 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 		prefix_len = strlen(prefix);
 	git_config(git_default_config, NULL);
 
-	if (read_cache() < 0)
-		die("index file corrupt");
-
 	argc = parse_options(argc, argv, prefix, builtin_ls_files_options,
 			ls_files_usage, 0);
 	el = add_exclude_list(&dir, EXC_CMDL, "--exclude option");
@@ -556,14 +555,7 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 		setup_work_tree();
 
 	pathspec = get_pathspec(prefix, argv);
-
-	/* be nice with submodule paths ending in a slash */
-	if (pathspec)
-		strip_trailing_slash_from_submodules();
-
-	/* Find common prefix for all pathspec's */
-	max_prefix = common_prefix(pathspec);
-	max_prefix_len = max_prefix ? strlen(max_prefix) : 0;
+	init_pathspec(&pathspec_struct, pathspec);
 
 	/* Treat unmatching pathspec elements as errors */
 	if (pathspec && error_unmatch) {
@@ -573,6 +565,23 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 		ps_matched = xcalloc(1, num);
 	}
 
+	if (!with_tree) {
+		memset(opts, 0, sizeof(*opts));
+		opts->pathspec = &pathspec_struct;
+		opts->read_staged = 1;
+		if (show_resolve_undo)
+			opts->read_resolve_undo = 1;
+		read_cache_filtered(opts);
+	} else {
+		read_cache();
+	}
+	/* be nice with submodule paths ending in a slash */
+	if (pathspec)
+		strip_trailing_slash_from_submodules();
+
+	max_prefix = common_prefix(pathspec);
+	max_prefix_len = max_prefix ? strlen(max_prefix) : 0;
+
 	if ((dir.flags & DIR_SHOW_IGNORED) && !exc_given)
 		die("ls-files --ignored needs some exclude pattern");
 
-- 
1.8.3.453.g1dfc63d