Merge branch 'lt/core-optim'

* lt/core-optim:
  Optimize symlink/directory detection
  Avoid some unnecessary lstat() calls
  is_racy_timestamp(): do not check timestamp for gitlinks
  diff-lib.c: rename check_work_tree_entity()
  diff: a submodule not checked out is not modified
  Add t7506 to test submodule related functions for git-status
  t4027: test diff for submodule with empty directory
  Make git-add behave more sensibly in a case-insensitive environment
  When adding files to the index, add support for case-independent matches
  Make unpack-tree update removed files before any updated files
  Make branch merging aware of underlying case-insensitive filsystems
  Add 'core.ignorecase' option
  Make hash_name_lookup able to do case-independent lookups
  Make "index_name_exists()" return the cache_entry it found
  Move name hashing functions into a file of its own
  Make unpack_trees_options bit flags actual bitfields

1 files changed, 27 insertions, 8 deletions

diff --git a/diff-lib.c b/diff-lib.c
index 9139e45fb9..fe2ccec7e6 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -337,22 +337,41 @@ int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 	}
 	return run_diff_files(revs, options);
 }
+
 /*
- * See if work tree has an entity that can be staged.  Return 0 if so,
- * return 1 if not and return -1 if error.
+ * Has the work tree entity been removed?
+ *
+ * Return 1 if it was removed from the work tree, 0 if an entity to be
+ * compared with the cache entry ce still exists (the latter includes
+ * the case where a directory that is not a submodule repository
+ * exists for ce that is a submodule -- it is a submodule that is not
+ * checked out).  Return negative for an error.
  */
-static int check_work_tree_entity(const struct cache_entry *ce, struct stat *st, char *symcache)
+static int check_removed(const struct cache_entry *ce, struct stat *st)
 {
 	if (lstat(ce->name, st) < 0) {
 		if (errno != ENOENT && errno != ENOTDIR)
 			return -1;
 		return 1;
 	}
-	if (has_symlink_leading_path(ce->name, symcache))
+	if (has_symlink_leading_path(ce_namelen(ce), ce->name))
 		return 1;
 	if (S_ISDIR(st->st_mode)) {
 		unsigned char sub[20];
-		if (resolve_gitlink_ref(ce->name, "HEAD", sub))
+
+		/*
+		 * If ce is already a gitlink, we can have a plain
+		 * directory (i.e. the submodule is not checked out),
+		 * or a checked out submodule.  Either case this is not
+		 * a case where something was removed from the work tree,
+		 * so we will return 0.
+		 *
+		 * Otherwise, if the directory is not a submodule
+		 * repository, that means ce which was a blob turned into
+		 * a directory --- the blob was removed!
+		 */
+		if (!S_ISGITLINK(ce->ce_mode) &&
+		    resolve_gitlink_ref(ce->name, "HEAD", sub))
 			return 1;
 	}
 	return 0;
@@ -402,7 +421,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			memset(&(dpath->parent[0]), 0,
 			       sizeof(struct combine_diff_parent)*5);
 
-			changed = check_work_tree_entity(ce, &st, symcache);
+			changed = check_removed(ce, &st);
 			if (!changed)
 				dpath->mode = ce_mode_from_stat(ce, st.st_mode);
 			else {
@@ -466,7 +485,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 		if (ce_uptodate(ce))
 			continue;
 
-		changed = check_work_tree_entity(ce, &st, symcache);
+		changed = check_removed(ce, &st);
 		if (changed) {
 			if (changed < 0) {
 				perror(ce->name);
@@ -527,7 +546,7 @@ static int get_stat_data(struct cache_entry *ce,
 	if (!cached) {
 		int changed;
 		struct stat st;
-		changed = check_work_tree_entity(ce, &st, cbdata->symcache);
+		changed = check_removed(ce, &st);
 		if (changed < 0)
 			return -1;
 		else if (changed) {