revision traversal: allow UNINTERESTING objects to be missing

Most of the existing codepaths were meant to treat missing uninteresting
objects to be a silently ignored non-error, but there were a few places
in handle_commit() and add_parents_to_list(), which are two key functions
in the revision traversal machinery, that cared:

 - When a tag refers to an object that we do not have, we barfed.  We
   ignore such a tag if it is painted as UNINTERESTING with this change.

 - When digging deeper into the ancestry chain of a commit that is already
   painted as UNINTERESTING, in order to paint its parents UNINTERESTING,
   we barfed if parse_parent() for a parent commit object failed.  We can
   ignore such a parent commit object.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/revision.c b/revision.c
index db60f06..1663ac8 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -183,8 +183,11 @@ static struct commit *handle_commit(struct rev_info *revs, struct object *object
                if (!tag->tagged)
                        die("bad tag");
                object = parse_object(tag->tagged->sha1);
-               if (!object)
+               if (!object) {
+                       if (flags & UNINTERESTING)
+                               return NULL;
                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
+               }
        }
 
        /*
@@ -479,9 +482,10 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
                while (parent) {
                        struct commit *p = parent->item;
                        parent = parent->next;
+                       if (p)
+                               p->object.flags |= UNINTERESTING;
                        if (parse_commit(p) < 0)
-                               return -1;
-                       p->object.flags |= UNINTERESTING;
+                               continue;
                        if (p->parents)
                                mark_parents_uninteresting(p);
                        if (p->object.flags & SEEN)

diff --git a/t/t5519-push-alternates.sh b/t/t5519-push-alternates.sh
index 6dfc55a..96be523 100755 (executable)
--- a/t/t5519-push-alternates.sh
+++ b/t/t5519-push-alternates.sh
@@ -103,4 +103,41 @@ test_expect_success 'bob works and pushes' '
        )
 '
 
+test_expect_success 'alice works and pushes yet again' '
+       (
+               # Alice does not care what Bob does.  She does not
+               # even have to be aware of his existence.  She just
+               # keeps working and pushing
+               cd alice-work &&
+               echo more and more alice >file &&
+               git commit -a -m sixth.1 &&
+               echo more and more alice >>file &&
+               git commit -a -m sixth.2 &&
+               echo more and more alice >>file &&
+               git commit -a -m sixth.3 &&
+               git push ../alice-pub
+       )
+'
+
+test_expect_success 'bob works and pushes again' '
+       (
+               cd alice-pub &&
+               git cat-file commit master >../bob-work/commit
+       )
+       (
+               # This time Bob does not pull from Alice, and
+               # the master branch at her public repository points
+               # at a commit Bob does not fully know about, but
+               # he happens to have the commit object (but not the
+               # necessary tree) in his repository from Alice.
+               # This should not prevent the push by Bob from
+               # succeeding.
+               cd bob-work &&
+               git hash-object -t commit -w commit &&
+               echo even more bob >file &&
+               git commit -a -m seventh &&
+               git push ../bob-pub
+       )
+'
+
 test_done