Merge branch 'js/merge-base-with-missing-commit'

Make sure failure return from merge_bases_many() is properly caught.

* js/merge-base-with-missing-commit:
  merge-ort/merge-recursive: do report errors in `merge_submodule()`
  merge-recursive: prepare for `merge_submodule()` to report errors
  commit-reach(repo_get_merge_bases_many_dirty): pass on errors
  commit-reach(repo_get_merge_bases_many): pass on "missing commits" errors
  commit-reach(get_octopus_merge_bases): pass on "missing commits" errors
  commit-reach(repo_get_merge_bases): pass on "missing commits" errors
  commit-reach(get_merge_bases_many_0): pass on "missing commits" errors
  commit-reach(merge_bases_many): pass on "missing commits" errors
  commit-reach(paint_down_to_common): start reporting errors
  commit-reach(paint_down_to_common): prepare for handling shallow commits
  commit-reach(repo_in_merge_bases_many): report missing commits
  commit-reach(repo_in_merge_bases_many): optionally expect missing commits
  commit-reach(paint_down_to_common): plug two memory leaks

builtin/fetch.c

@@ -981,6 +981,8 @@ static int update_local_ref(struct ref *ref,
 		uint64_t t_before = getnanotime();
 		fast_forward = repo_in_merge_bases(the_repository, current,
 						   updated);
+		if (fast_forward < 0)
+			exit(128);
 		forced_updates_ms += (getnanotime() - t_before) / 1000000;
 	} else {
 		fast_forward = 1;