Merge branch 'hv/submodule-not-yet-pushed-fix' into maint

The code in "git push" to compute if any commit being pushed in the
superproject binds a commit in a submodule that hasn't been pushed
out was overly inefficient, making it unusable even for a small
project that does not have any submodule but have a reasonable
number of refs.

* hv/submodule-not-yet-pushed-fix:
  submodule_needs_pushing(): explain the behaviour when we cannot answer
  batch check whether submodule needs pushing into one call
  serialize collection of refs that contain submodule changes
  serialize collection of changed submodules

1 files changed, 21 insertions, 8 deletions

diff --git a/transport.c b/transport.c
index d57e8dec28..f482869057 100644
--- a/transport.c
+++ b/transport.c
@@ -949,23 +949,36 @@ int transport_push(struct transport *transport,
 
 		if ((flags & TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND) && !is_bare_repository()) {
 			struct ref *ref = remote_refs;
+			struct sha1_array commits = SHA1_ARRAY_INIT;
+
 			for (; ref; ref = ref->next)
-				if (!is_null_oid(&ref->new_oid) &&
-				    !push_unpushed_submodules(ref->new_oid.hash,
-					    transport->remote->name))
-				    die ("Failed to push all needed submodules!");
+				if (!is_null_oid(&ref->new_oid))
+					sha1_array_append(&commits, ref->new_oid.hash);
+
+			if (!push_unpushed_submodules(&commits, transport->remote->name)) {
+				sha1_array_clear(&commits);
+				die("Failed to push all needed submodules!");
+			}
+			sha1_array_clear(&commits);
 		}
 
 		if ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
 			      TRANSPORT_RECURSE_SUBMODULES_CHECK)) && !is_bare_repository()) {
 			struct ref *ref = remote_refs;
 			struct string_list needs_pushing = STRING_LIST_INIT_DUP;
+			struct sha1_array commits = SHA1_ARRAY_INIT;
 
 			for (; ref; ref = ref->next)
-				if (!is_null_oid(&ref->new_oid) &&
-				    find_unpushed_submodules(ref->new_oid.hash,
-					    transport->remote->name, &needs_pushing))
-					die_with_unpushed_submodules(&needs_pushing);
+				if (!is_null_oid(&ref->new_oid))
+					sha1_array_append(&commits, ref->new_oid.hash);
+
+			if (find_unpushed_submodules(&commits, transport->remote->name,
+						&needs_pushing)) {
+				sha1_array_clear(&commits);
+				die_with_unpushed_submodules(&needs_pushing);
+			}
+			string_list_clear(&needs_pushing, 0);
+			sha1_array_clear(&commits);
 		}
 
 		push_ret = transport->push_refs(transport, remote_refs, flags);