X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=delta.h;h=09b2e1eed5dfc772feb38715f051eff43570d4cb;hb=ac4c758adcf52b913b82d481626b0f8648e95475;hp=31d1820f80f2887d51808170fc86585ada42d42e;hpb=302ebfe52192fff9a2c1c612dff22325fd073acc;p=git.git

diff --git a/delta.h b/delta.h
index 31d1820f..09b2e1ee 100644
--- a/delta.h
+++ b/delta.h
@@ -2,11 +2,11 @@
 #define DELTA_H
 
 /* handling of delta buffers */
-extern void *diff_delta(void *from_buf, unsigned long from_size,
-			void *to_buf, unsigned long to_size,
+extern 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);
 extern void *patch_delta(void *src_buf, unsigned long src_size,
-			 void *delta_buf, unsigned long delta_size,
+			 const void *delta_buf, unsigned long delta_size,
 			 unsigned long *dst_size);
 
 /* the smallest possible delta size is 4 bytes */
@@ -16,17 +16,18 @@ extern void *patch_delta(void *src_buf, unsigned long src_size,
  * This must be called twice on the delta data buffer, first to get the
  * expected reference buffer size, and again to get the result buffer size.
  */
-static inline unsigned long get_delta_hdr_size(const unsigned char **datap)
+static inline unsigned long get_delta_hdr_size(const unsigned char **datap,
+					       const unsigned char *top)
 {
 	const unsigned char *data = *datap;
-	unsigned char cmd = *data++;
-	unsigned long size = cmd & ~0x80;
-	int i = 7;
-	while (cmd & 0x80) {
+	unsigned char cmd;
+	unsigned long size = 0;
+	int i = 0;
+	do {
 		cmd = *data++;
 		size |= (cmd & ~0x80) << i;
 		i += 7;
-	}
+	} while (cmd & 0x80 && data < top);
 	*datap = data;
 	return size;
 }