diff options
| -rw-r--r-- | sha1_file.c | 73 |
1 files changed, 69 insertions, 4 deletions
diff --git a/sha1_file.c b/sha1_file.c index 698b43cfc..5695c962f 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -601,9 +601,70 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l return unpack_sha1_rest(&stream, hdr, *size); } -/* Returns 0 on fast-path success, returns 1 on deltified - * and need to unpack to see info. - */ +static int packed_delta_info(unsigned char *base_sha1, + unsigned long delta_size, + unsigned long left, + char *type, + unsigned long *sizep) +{ + unsigned char *data; + unsigned char delta_head[64]; + int i; + unsigned char cmd; + unsigned long data_size, result_size, base_size, verify_base_size; + z_stream stream; + int st; + + if (left < 20) + die("truncated pack file"); + if (sha1_object_info(base_sha1, type, &base_size)) + die("cannot get info for delta-pack base"); + + data = base_sha1 + 20; + data_size = left - 20; + + memset(&stream, 0, sizeof(stream)); + + stream.next_in = data; + stream.avail_in = data_size; + stream.next_out = delta_head; + stream.avail_out = sizeof(delta_head); + + inflateInit(&stream); + st = inflate(&stream, Z_FINISH); + inflateEnd(&stream); + if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) + die("delta data unpack-initial failed"); + + /* Examine the initial part of the delta to figure out + * the result size. Verify the base size while we are at it. + */ + data = delta_head; + verify_base_size = i = 0; + cmd = *data++; + while (cmd) { + if (cmd & 1) + verify_base_size |= *data++ << i; + i += 8; + cmd >>= 1; + } + + /* Read the result size */ + result_size = i = 0; + cmd = *data++; + while (cmd) { + if (cmd & 1) + result_size |= *data++ << i; + i += 8; + cmd >>= 1; + } + if (verify_base_size != base_size) + die("delta base size mismatch"); + + *sizep = result_size; + return 0; +} + static int packed_object_info(struct pack_entry *entry, char *type, unsigned long *sizep) { @@ -614,12 +675,16 @@ static int packed_object_info(struct pack_entry *entry, offset = entry->offset; if (p->pack_size - 5 < offset) die("object offset outside of pack file"); + + if (use_packed_git(p)) + die("cannot map packed file"); + pack = p->pack_base + offset; size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4]; left = p->pack_size - offset - 5; switch (*pack) { case 'D': - return 1; + return packed_delta_info(pack+5, size, left, type, sizep); break; case 'C': strcpy(type, "commit"); |