diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 71 |
1 files changed, 47 insertions, 24 deletions
diff --git a/sha1_file.c b/sha1_file.c index d5616dca08..3401301444 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -248,27 +248,30 @@ static int link_alt_odb_entry(const char * entry, int len, const char * relative const char *objdir = get_object_directory(); struct alternate_object_database *ent; struct alternate_object_database *alt; - /* 43 = 40-byte + 2 '/' + terminating NUL */ - int pfxlen = len; - int entlen = pfxlen + 43; - int base_len = -1; + int pfxlen, entlen; + struct strbuf pathbuf = STRBUF_INIT; if (!is_absolute_path(entry) && relative_base) { - /* Relative alt-odb */ - if (base_len < 0) - base_len = strlen(relative_base) + 1; - entlen += base_len; - pfxlen += base_len; + strbuf_addstr(&pathbuf, real_path(relative_base)); + strbuf_addch(&pathbuf, '/'); } - ent = xmalloc(sizeof(*ent) + entlen); + strbuf_add(&pathbuf, entry, len); - if (!is_absolute_path(entry) && relative_base) { - memcpy(ent->base, relative_base, base_len - 1); - ent->base[base_len - 1] = '/'; - memcpy(ent->base + base_len, entry, len); - } - else - memcpy(ent->base, entry, pfxlen); + normalize_path_copy(pathbuf.buf, pathbuf.buf); + + pfxlen = strlen(pathbuf.buf); + + /* + * The trailing slash after the directory name is given by + * this function at the end. Remove duplicates. + */ + while (pfxlen && pathbuf.buf[pfxlen-1] == '/') + pfxlen -= 1; + + entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */ + ent = xmalloc(sizeof(*ent) + entlen); + memcpy(ent->base, pathbuf.buf, pfxlen); + strbuf_release(&pathbuf); ent->name = ent->base + pfxlen + 1; ent->base[pfxlen + 3] = '/'; @@ -380,7 +383,7 @@ void add_to_alternates_file(const char *reference) { struct lock_file *lock = xcalloc(1, sizeof(struct lock_file)); int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR); - char *alt = mkpath("%s/objects\n", reference); + char *alt = mkpath("%s\n", reference); write_or_die(fd, alt, strlen(alt)); if (commit_lock_file(lock)) die("could not close alternates file"); @@ -1217,14 +1220,34 @@ static int experimental_loose_object(unsigned char *map) unsigned int word; /* - * Is it a zlib-compressed buffer? If so, the first byte - * must be 0x78 (15-bit window size, deflated), and the - * first 16-bit word is evenly divisible by 31. If so, - * we are looking at the official format, not the experimental - * one. + * We must determine if the buffer contains the standard + * zlib-deflated stream or the experimental format based + * on the in-pack object format. Compare the header byte + * for each format: + * + * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7 + * Experimental pack-based : Stttssss : ttt = 1,2,3,4 + * + * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be + * in standard loose-object format, UNLESS it is a Git-pack + * format object *exactly* 8 bytes in size when inflated. + * + * However, RFC1950 also specifies that the 1st 16-bit word + * must be divisible by 31 - this checksum tells us our buffer + * is in the standard format, giving a false positive only if + * the 1st word of the Git-pack format object happens to be + * divisible by 31, ie: + * ((byte0 * 256) + byte1) % 31 = 0 + * => 0ttt10000www1000 % 31 = 0 + * + * As it happens, this case can only arise for www=3 & ttt=1 + * - ie, a Commit object, which would have to be 8 bytes in + * size. As no Commit can be that small, we find that the + * combination of these two criteria (bitmask & checksum) + * can always correctly determine the buffer format. */ word = (map[0] << 8) + map[1]; - if (map[0] == 0x78 && !(word % 31)) + if ((map[0] & 0x8F) == 0x08 && !(word % 31)) return 0; else return 1; |