X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=diff-delta.c;h=b2ae7b5e6c3b4aa409ccfa60f67d5c8eb1690504;hb=6b17c674aa517c4b22cd88809fcf1532b8204fbf;hp=480f03cd16841945352c176b50300613fbf71175;hpb=a310d4349467d78266f38d29e500c77b96ee5bef;p=git.git

diff --git a/diff-delta.c b/diff-delta.c
index 480f03cd..b2ae7b5e 100644
--- a/diff-delta.c
+++ b/diff-delta.c
@@ -203,7 +203,8 @@ static void delta_cleanup(bdfile_t *bdf)
 
 void *diff_delta(void *from_buf, unsigned long from_size,
 		 void *to_buf, unsigned long to_size,
-		 unsigned long *delta_size)
+		 unsigned long *delta_size,
+		 unsigned long max_size)
 {
 	int i, outpos, outsize, inscnt, csize, msize, moff;
 	unsigned int fp;
@@ -227,28 +228,22 @@ void *diff_delta(void *from_buf, unsigned long from_size,
 	top = to_buf + to_size;
 
 	/* store reference buffer size */
-	orig = out + outpos++;
-	*orig = i = 0;
-	do {
-		if (from_size & 0xff) {
-			*orig |= (1 << i);
-			out[outpos++] = from_size;
-		}
-		i++;
-		from_size >>= 8;
-	} while (from_size);
+	out[outpos++] = from_size;
+	from_size >>= 7;
+	while (from_size) {
+		out[outpos - 1] |= 0x80;
+		out[outpos++] = from_size;
+		from_size >>= 7;
+	}
 
 	/* store target buffer size */
-	orig = out + outpos++;
-	*orig = i = 0;
-	do {
-		if (to_size & 0xff) {
-			*orig |= (1 << i);
-			out[outpos++] = to_size;
-		}
-		i++;
-		to_size >>= 8;
-	} while (to_size);
+	out[outpos++] = to_size;
+	to_size >>= 7;
+	while (to_size) {
+		out[outpos - 1] |= 0x80;
+		out[outpos++] = to_size;
+		to_size >>= 7;
+	}
 
 	inscnt = 0;
 	moff = 0;
@@ -311,6 +306,12 @@ void *diff_delta(void *from_buf, unsigned long from_size,
 			*orig = i;
 		}
 
+		if (max_size && outpos > max_size) {
+			free(out);
+			delta_cleanup(&bdf);
+			return NULL;
+		}
+
 		/* next time around the largest possible output is 1 + 4 + 3 */
 		if (outpos > outsize - 8) {
 			void *tmp = out;