few branch... tests have been failing sporadically due to the undefined rev order in rev-list (at least in git 2.22).

the fix:
	add --topo-order qualifier to the rev-list to make the order to be stable across different test.

still failing tests:

test/error.t                   (Wstat: 0 Tests: 17 Failed: 1)
  Failed test:  17
  Parse errors: No plan found in TAP output
test/pull-merge.t              (Wstat: 0 Tests: 13 Failed: 1)
  Failed test:  8
test/push-after-init.t         (Wstat: 0 Tests: 0 Failed: 0)
  Parse errors: No plan found in TAP output
test/push-new-branch.t         (Wstat: 0 Tests: 0 Failed: 0)
  Parse errors: No plan found in TAP output
test/push.t                    (Wstat: 0 Tests: 17 Failed: 2)
  Failed tests:  3-4

Author: serbogus

lib/git-subrepo

@@ -704,7 +704,7 @@ subrepo:branch() {
     local prev_commit=
     local ancestor=
     o "Create new commits with parents into the subrepo fetch"
-    OUT=true RUN git rev-list --reverse --ancestry-path  "$subrepo_parent..HEAD"
+    OUT=true RUN git rev-list --reverse --ancestry-path --topo-order "$subrepo_parent..HEAD"
     local commit_list="$output"
     for commit in $commit_list; do
       o "Working on $commit"