3 files changed, 67 insertions, 24 deletions

diff --git a/cache.h b/cache.h
index 80eeeb7db8..1bf2d4bde6 100644
--- a/cache.h
+++ b/cache.h
@@ -729,6 +729,8 @@ extern int has_symlink_or_noent_leading_path(const char *name, int len);
 extern int has_dirs_only_path(const char *name, int len, int prefix_len);
 extern void invalidate_lstat_cache(const char *name, int len);
 extern void clear_lstat_cache(void);
+extern void schedule_dir_for_removal(const char *name, int len);
+extern void remove_scheduled_dirs(void);
 
 extern struct alternate_object_database {
 	struct alternate_object_database *next;
diff --git a/symlinks.c b/symlinks.c
index 51672868d1..1d6b35b858 100644
--- a/symlinks.c
+++ b/symlinks.c
@@ -245,3 +245,62 @@ int has_dirs_only_path(const char *name, int len, int prefix_len)
 			   FL_DIR|FL_FULLPATH, prefix_len) &
 		FL_DIR;
 }
+
+static struct removal_def {
+	char path[PATH_MAX];
+	int len;
+} removal;
+
+static void do_remove_scheduled_dirs(int new_len)
+{
+	while (removal.len > new_len) {
+		removal.path[removal.len] = '\0';
+		if (rmdir(removal.path))
+			break;
+		do {
+			removal.len--;
+		} while (removal.len > new_len &&
+			 removal.path[removal.len] != '/');
+	}
+	removal.len = new_len;
+	return;
+}
+
+void schedule_dir_for_removal(const char *name, int len)
+{
+	int match_len, last_slash, i, previous_slash;
+
+	match_len = last_slash = i =
+		longest_path_match(name, len, removal.path, removal.len,
+				   &previous_slash);
+	/* Find last slash inside 'name' */
+	while (i < len) {
+		if (name[i] == '/')
+			last_slash = i;
+		i++;
+	}
+
+	/*
+	 * If we are about to go down the directory tree, we check if
+	 * we must first go upwards the tree, such that we then can
+	 * remove possible empty directories as we go upwards.
+	 */
+	if (match_len < last_slash && match_len < removal.len)
+		do_remove_scheduled_dirs(match_len);
+	/*
+	 * If we go deeper down the directory tree, we only need to
+	 * save the new path components as we go down.
+	 */
+	if (match_len < last_slash) {
+		memcpy(&removal.path[match_len], &name[match_len],
+		       last_slash - match_len);
+		removal.len = last_slash;
+	}
+	return;
+}
+
+void remove_scheduled_dirs(void)
+{
+	do_remove_scheduled_dirs(0);
+	return;
+}
diff --git a/unpack-trees.c b/unpack-trees.c
index 2293158850..e3c3fa12aa 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -52,36 +52,17 @@ static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
 	add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|ADD_CACHE_SKIP_DFCHECK);
 }
 
-/* Unlink the last component and attempt to remove leading
- * directories, in case this unlink is the removal of the
- * last entry in the directory -- empty directories are removed.
+/*
+ * Unlink the last component and schedule the leading directories for
+ * removal, such that empty directories get removed.
  */
 static void unlink_entry(struct cache_entry *ce)
 {
-	char *cp, *prev;
-	char *name = ce->name;
-
 	if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
 		return;
-	if (unlink(name))
+	if (unlink(ce->name))
 		return;
-	prev = NULL;
-	while (1) {
-		int status;
-		cp = strrchr(name, '/');
-		if (prev)
-			*prev = '/';
-		if (!cp)
-			break;
-
-		*cp = 0;
-		status = rmdir(name);
-		if (status) {
-			*cp = '/';
-			break;
-		}
-		prev = cp;
-	}
+	schedule_dir_for_removal(ce->name, ce_namelen(ce));
 }
 
 static struct checkout state;
@@ -117,6 +98,7 @@ static int check_updates(struct unpack_trees_options *o)
 			continue;
 		}
 	}
+	remove_scheduled_dirs();
 
 	for (i = 0; i < index->cache_nr; i++) {
 		struct cache_entry *ce = index->cache[i];