diff.h: reduce unnecessary includes

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/attr.c b/attr.c
index 2d8aeb8b58..ddf2b0cbc2 100644
--- a/attr.c
+++ b/attr.c
@@ -20,6 +20,7 @@
 #include "object-store.h"
 #include "setup.h"
 #include "thread-utils.h"
+#include "tree-walk.h"
 
 const char git_attr__true[] = "(builtin)true";
 const char git_attr__false[] = "\0(builtin)false";