Move buffer_is_binary() to xdiff-interface.h

We already have two instances where we want to determine if a buffer
contains binary data as opposed to text.

[jc: cherry-picked 6bfce93e from 'master']

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 6 deletions

diff --git a/diff.c b/diff.c
index af282ddd8..dc6da5e25 100644
--- a/diff.c
+++ b/diff.c
@@ -1107,10 +1107,8 @@ static void setup_diff_attr_check(struct git_attr_check *check)
 	check->attr = attr_diff;
 }
 
-#define FIRST_FEW_BYTES 8000
 static int file_is_binary(struct diff_filespec *one)
 {
-	unsigned long sz;
 	struct git_attr_check attr_diff_check;
 
 	setup_diff_attr_check(&attr_diff_check);
@@ -1127,10 +1125,7 @@ static int file_is_binary(struct diff_filespec *one)
 			return 0;
 		diff_populate_filespec(one, 0);
 	}
-	sz = one->size;
-	if (FIRST_FEW_BYTES < sz)
-		sz = FIRST_FEW_BYTES;
-	return !!memchr(one->data, 0, sz);
+	return buffer_is_binary(one->data, one->size);
 }
 
 static void builtin_diff(const char *name_a,