untracked cache: mark index dirty if untracked cache is updated

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -289,6 +289,7 @@ static inline unsigned int canon_mode(unsigned int mode)
 #define RESOLVE_UNDO_CHANGED	(1 << 4)
 #define CACHE_TREE_CHANGED	(1 << 5)
 #define SPLIT_INDEX_ORDERED	(1 << 6)
+#define UNTRACKED_CHANGED	(1 << 7)
 
 struct split_index;
 struct untracked_cache;

dir.c

@@ -1934,6 +1934,15 @@ int read_directory(struct dir_struct *dir, const char *path, int len, const stru
 				 dir->untracked->gitignore_invalidated,
 				 dir->untracked->dir_invalidated,
 				 dir->untracked->dir_opened);
+		if (dir->untracked == the_index.untracked &&
+		    (dir->untracked->dir_opened ||
+		     dir->untracked->gitignore_invalidated ||
+		     dir->untracked->dir_invalidated))
+			the_index.cache_changed |= UNTRACKED_CHANGED;
+		if (dir->untracked != the_index.untracked) {
+			free(dir->untracked);
+			dir->untracked = NULL;
+		}
 	}
 	return dir->nr;
 }

read-cache.c

@@ -44,7 +44,7 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce,
 /* changes that can be kept in $GIT_DIR/index (basically all extensions) */
 #define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \
 		 CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \
-		 SPLIT_INDEX_ORDERED)
+		 SPLIT_INDEX_ORDERED | UNTRACKED_CHANGED)
 
 struct index_state the_index;
 static const char *alternate_index_output;