[PATCH] denser delta header encoding

[git.git] / patch-delta.c

diff --git a/patch-delta.c b/patch-delta.c
index a8d75ee..b68dd13 100644 (file)
--- a/patch-delta.c
+++ b/patch-delta.c
@@ -22,33 +22,33 @@ void *patch_delta(void *src_buf, unsigned long src_size,
        unsigned long size;
        int i;
 
-       /* the smallest delta size possible is 6 bytes */
-       if (delta_size < 6)
+       /* the smallest delta size possible is 4 bytes */
+       if (delta_size < 4)
                return NULL;
 
        data = delta_buf;
        top = delta_buf + delta_size;
 
        /* make sure the orig file size matches what we expect */
-       size = i = 0;
        cmd = *data++;
-       while (cmd) {
-               if (cmd & 1)
-                       size |= *data++ << i;
-               i += 8;
-               cmd >>= 1;
+       size = cmd & ~0x80;
+       i = 7;
+       while (cmd & 0x80) {
+               cmd = *data++;
+               size |= (cmd & ~0x80) << i;
+               i += 7;
        }
        if (size != src_size)
                return NULL;
 
        /* now the result size */
-       size = i = 0;
        cmd = *data++;
-       while (cmd) {
-               if (cmd & 1)
-                       size |= *data++ << i;
-               i += 8;
-               cmd >>= 1;
+       size = cmd & ~0x80;
+       i = 7;
+       while (cmd & 0x80) {
+               cmd = *data++;
+               size |= (cmd & ~0x80) << i;
+               i += 7;
        }
        dst_buf = malloc(size);
        if (!dst_buf)