> Jonathan Tan <jonathantanmy@xxxxxxxxxx> writes:
>
> > init.defaultBranch::
> > Allows overriding the default branch name e.g. when initializing
> > - a new repository or when cloning an empty repository.
> > + a new repository.
>
> Looking good.
>
> > diff --git a/builtin/clone.c b/builtin/clone.c
> > index 211d4f54b0..77fdc61f4d 100644
> > --- a/builtin/clone.c
> > +++ b/builtin/clone.c
> > @@ -1330,10 +1330,21 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
> > remote_head = NULL;
> > option_no_checkout = 1;
> > if (!option_bare) {
> > - const char *branch = git_default_branch_name();
> > - char *ref = xstrfmt("refs/heads/%s", branch);
> > + const char *branch;
> > + char *ref;
> > +
> > + if (transport_ls_refs_options.unborn_head_target &&
> > + skip_prefix(transport_ls_refs_options.unborn_head_target,
> > + "refs/heads/", &branch)) {
> > + ref = transport_ls_refs_options.unborn_head_target;
> > + transport_ls_refs_options.unborn_head_target = NULL;
> > + } else {
> > + branch = git_default_branch_name();
> > + ref = xstrfmt("refs/heads/%s", branch);
> > + }
> >
> > install_branch_config(0, branch, remote_name, ref);
> > + create_symref("HEAD", ref, "");
> > free(ref);
>
> OK, we used to say "point our HEAD always to the local default
> name", and the code is still there in the else clause. But when the
> transport found what name the other side uses, we use that name
> instead.
>
> I presume that clearing transport_ls_ref_options.unborn_head_target
> is to take ownership of this piece of memory ourselves?
Yes - just to be consistent with the other branch where "ref" needs to
be freed.
> We didn't call create_symref() in the original code, but now we do.
> Is this a valid bugfix even if we did not have this "learn remote
> symref even for unborn HEAD" feature? Or is the original codepath
> now somehow got broken with an extra create_symref() that we used
> not to do, but now we do?
Ah...now I think I see what you and Peff [1] were saying. Yes I think
the symref creation is not necessary when we use the default branch name
(like we currently do). I'll verify and write back with my findings in
the next version.
[1] https://lore.kernel.org/git/YBCf8SI3fK+rDyox@xxxxxxxxxxxxxxxxxxxxxxx/
>
> > @@ -1385,5 +1396,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
> > junk_mode = JUNK_LEAVE_ALL;
> >
> > strvec_clear(&transport_ls_refs_options.ref_prefixes);
> > + free(transport_ls_refs_options.unborn_head_target);
> > return err;
> > }
> > diff --git a/connect.c b/connect.c
> > index 328c279250..879669df93 100644
> > --- a/connect.c
> > +++ b/connect.c
> > @@ -376,7 +376,8 @@ struct ref **get_remote_heads(struct packet_reader *reader,
> > }
> >
> > /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
> > -static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
> > +static int process_ref_v2(struct packet_reader *reader, struct ref ***list,
> > + char **unborn_head_target)
> > {
> > int ret = 1;
> > int i = 0;
> > @@ -397,6 +398,25 @@ static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
> > goto out;
> > }
> >
> > + if (!strcmp("unborn", line_sections.items[i].string)) {
> > + i++;
> > + if (unborn_head_target &&
> > + !strcmp("HEAD", line_sections.items[i++].string)) {
> > + /*
> > + * Look for the symref target (if any). If found,
> > + * return it to the caller.
> > + */
> > + for (; i < line_sections.nr; i++) {
> > + const char *arg = line_sections.items[i].string;
> > +
> > + if (skip_prefix(arg, "symref-target:", &arg)) {
> > + *unborn_head_target = xstrdup(arg);
> > + break;
> > + }
> > + }
> > + }
> > + goto out;
> > + }
>
> We split the line and notice that the first token is "unborn"; if
> the caller is not interested in the unborn head, we just skip the
> rest, but otherwise, if it is about HEAD (i.e. we do not care if a
> dangling symref that is not HEAD is reported), we notice the target
> in unborn_head_target.
>
> OK. We already saw how this is used in cmd_clone().
>
> > @@ -461,6 +481,8 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
> > const char *hash_name;
> > struct strvec *ref_prefixes = transport_options ?
> > &transport_options->ref_prefixes : NULL;
> > + char **unborn_head_target = transport_options ?
> > + &transport_options->unborn_head_target : NULL;
>
> So any caller that passes transport_options will get the unborn head
> information for free? The other callers are in fetch-pack.c and
> transport.c, which presumably are about fetching and not cloning.
>
> I recall discussions on filling a missing refs/remotes/X/HEAD when
> we fetch from X and learn where X points at. Such an extension can
> be done on top of this mechanism to pass transport_options from the
> fetch codepath, I presume?
I don't recall those discussions, but I think that we can do that (as
long as HEAD points to a branch that is part of the refspec we're
fetching, because the ref-prefix check still applies).
> Thanks. I tried to follow the thought in the patches aloud, and it
> was mostly a pleasant read.
Thanks.
