checkout-index: plug memory leak from prefix_path()

diff --git a/diff-delta.c b/diff-delta.c
index 1188b31cd0f1e2f3a1fc2096a10243a03b439021..5bc22047f8715b0b1e628ab5ba93afa68e2ccc9e 100644 (file)
--- a/diff-delta.c
+++ b/diff-delta.c
@@ -131,8 +131,8 @@ static struct index ** delta_index(const unsigned char *buf,
 /* the maximum size for any opcode */
 #define MAX_OP_SIZE COPYOP_SIZE(0xffffffff, 0xffffffff)
 
-void *diff_delta(void *from_buf, unsigned long from_size,
-                void *to_buf, unsigned long to_size,
+void *diff_delta(const void *from_buf, unsigned long from_size,
+                const void *to_buf, unsigned long to_size,
                 unsigned long *delta_size,
                 unsigned long max_size)
 {