send-pack: support pushing from a shallow clone via http

diff --git a/fetch-pack.c b/fetch-pack.c
index 34c544d0ca9e32dd2f28c572100040f054476db5..a2d1b4ab28aa94b6e685cd7bac1fb18ed1a6d96d 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -993,6 +993,33 @@ static void update_shallow(struct fetch_pack_args *args,
                sha1_array_append(&ref, sought[i]->old_sha1);
        si->ref = &ref;
 
+       if (args->update_shallow) {
+               /*
+                * remote is also shallow, .git/shallow may be updated
+                * so all refs can be accepted. Make sure we only add
+                * shallow roots that are actually reachable from new
+                * refs.
+                */
+               struct sha1_array extra = SHA1_ARRAY_INIT;
+               unsigned char (*sha1)[20] = si->shallow->sha1;
+               assign_shallow_commits_to_refs(si, NULL, NULL);
+               if (!si->nr_ours && !si->nr_theirs) {
+                       sha1_array_clear(&ref);
+                       return;
+               }
+               for (i = 0; i < si->nr_ours; i++)
+                       sha1_array_append(&extra, sha1[si->ours[i]]);
+               for (i = 0; i < si->nr_theirs; i++)
+                       sha1_array_append(&extra, sha1[si->theirs[i]]);
+               setup_alternate_shallow(&shallow_lock,
+                                       &alternate_shallow_file,
+                                       &extra);
+               commit_lock_file(&shallow_lock);
+               sha1_array_clear(&extra);
+               sha1_array_clear(&ref);
+               return;
+       }
+
        /*
         * remote is also shallow, check what ref is safe to update
         * without updating .git/shallow