promisor-remote: use repository_format_partial_clone

A remote specified using the extensions.partialClone config
option should be considered a promisor remote too.

For simplicity and to make things predictable, this promisor
remote should be either always the last one we try to get
objects from, or the first one. So it should always be either
at the end of the promisor remote list, or at its start.

We decided to make it the last one we try, because it is
likely that someone using many promisor remotes is doing so
because the other promisor remotes are better for some reason
(maybe they are closer or faster for some kind of objects)
than the origin, and the origin is likely to be the remote
specified by extensions.partialClone.

This justification is not very strong, but one choice had to
be made, and anyway the long term plan should be to make the
order somehow fully configurable.

Signed-off-by: Christian Couder <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: chriscool

promisor-remote.c

@@ -40,6 +40,18 @@ static struct promisor_remote *promisor_remote_lookup(const char *remote_name,
 	return NULL;
 }
 
+static void promisor_remote_move_to_tail(struct promisor_remote *r,
+					 struct promisor_remote *previous)
+{
+	if (previous)
+		previous->next = r->next;
+	else
+		promisors = r->next ? r->next : r;
+	r->next = NULL;
+	*promisors_tail = r;
+	promisors_tail = &r->next;
+}
+
 static int promisor_remote_config(const char *var, const char *value, void *data)
 {
 	const char *name;
@@ -76,6 +88,17 @@ static void promisor_remote_init(void)
 	initialized = 1;
 
 	git_config(promisor_remote_config, NULL);
+
+	if (repository_format_partial_clone) {
+		struct promisor_remote *o, *previous;
+
+		o = promisor_remote_lookup(repository_format_partial_clone,
+					   &previous);
+		if (o)
+			promisor_remote_move_to_tail(o, previous);
+		else
+			promisor_remote_new(repository_format_partial_clone);
+	}
 }
 
 static void promisor_remote_clear(void)