git-rev-parse: Allow a "zeroth" parent of a commit - the commit itself.

This sounds nonsensical, but it's useful to make sure that the result is
a commit.

For example, "git-rev-parse v2.6.12" will return the _tag_ object for
v2.6.12, but "git-rev-parse v2.6.12^0" will return the _commit_ object
associated with that tag (and v2.6.12^1 will return the first parent).

Also, since the "parent" code will actually parse the commit, this,
together with the "--verify" flag, will verify not only that the result
is a single SHA1, but will also have verified that it's a proper commit
that we can see.
This commit is contained in:
Linus Torvalds 2005-07-11 18:27:25 -07:00
parent e33b2ef8f5
commit 79162bb8ad

View File

@ -97,6 +97,10 @@ static int get_parent(char *name, unsigned char *result, int idx)
return -1;
if (parse_commit(commit))
return -1;
if (!idx) {
memcpy(result, commit->object.sha1, 20);
return 0;
}
p = commit->parents;
while (p) {
if (!--idx) {
@ -238,7 +242,7 @@ static int get_extended_sha1(char *name, unsigned char *sha1)
int len = strlen(name);
parent = 1;
if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
if (len > 2 && name[len-1] >= '0' && name[len-1] <= '9') {
parent = name[len-1] - '0';
len--;
}