Merge branch 'lt/maint-diff-reduce-lstat' into maint

* lt/maint-diff-reduce-lstat:
  Teach 'git checkout' to preload the index contents
  Avoid unnecessary 'lstat()' calls in 'get_stat_data()'

Author: gitster

builtin-checkout.c

@@ -216,7 +216,7 @@ static int checkout_paths(struct tree *source_tree, const char **pathspec,
 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 
 	newfd = hold_locked_index(lock_file, 1);
-	if (read_cache() < 0)
+	if (read_cache_preload(pathspec) < 0)
 		return error("corrupt index file");
 
 	if (source_tree)
@@ -366,7 +366,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 	int newfd = hold_locked_index(lock_file, 1);
 
-	if (read_cache() < 0)
+	if (read_cache_preload(NULL) < 0)
 		return error("corrupt index file");
 
 	if (opts->force) {

diff-lib.c

@@ -214,7 +214,7 @@ static int get_stat_data(struct cache_entry *ce,
 	const unsigned char *sha1 = ce->sha1;
 	unsigned int mode = ce->ce_mode;
 
-	if (!cached) {
+	if (!cached && !ce_uptodate(ce)) {
 		int changed;
 		struct stat st;
 		changed = check_removed(ce, &st);