diff options
| -rw-r--r-- | sha1_name.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/sha1_name.c b/sha1_name.c index 6744bbb..133af3b 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -191,9 +191,29 @@ static int get_parent(const char *name, int len, return -1; } +static int get_nth_ancestor(const char *name, int len, + unsigned char *result, int generation) +{ + unsigned char sha1[20]; + int ret = get_sha1_1(name, len, sha1); + if (ret) + return ret; + + while (generation--) { + struct commit *commit = lookup_commit_reference(sha1); + + if (!commit || parse_commit(commit) || !commit->parents) + return -1; + memcpy(sha1, commit->parents->item->object.sha1, 20); + } + memcpy(result, sha1, 20); + return 0; +} + static int get_sha1_1(const char *name, int len, unsigned char *sha1) { int parent, ret; + const char *cp; /* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */ if (len > 2 && name[len-2] == '^' && @@ -210,6 +230,27 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1) if (parent >= 0) return get_parent(name, len, sha1, parent); + /* "name~3" is "name^^^", + * "name~12" is "name^^^^^^^^^^^^", and + * "name~" and "name~0" are name -- not "name^0"! + */ + parent = 0; + for (cp = name + len - 1; name <= cp; cp--) { + int ch = *cp; + if ('0' <= ch && ch <= '9') + continue; + if (ch != '~') + parent = -1; + break; + } + if (!parent && *cp == '~') { + int len1 = cp - name; + cp++; + while (cp < name + len) + parent = parent * 10 + *cp++ - '0'; + return get_nth_ancestor(name, len1, sha1, parent); + } + ret = get_sha1_basic(name, len, sha1); if (!ret) return 0; |