test_cmp_rev HEAD $before
'
+test_expect_success 'a "merge" into a root commit is a fast-forward' '
+ head=$(git rev-parse HEAD) &&
+ cat >script-from-scratch <<-EOF &&
+ reset [new root]
+ merge $head
+ EOF
+ test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
+ test_tick &&
+ git rebase -i -r HEAD^ &&
+ test_cmp_rev HEAD $head
+'
+
+test_expect_success 'A root commit can be a cousin, treat it that way' '
+ git checkout --orphan khnum &&
+ test_commit yama &&
+ git checkout -b asherah master &&
+ test_commit shamkat &&
+ git merge --allow-unrelated-histories khnum &&
+ test_tick &&
+ git rebase -f -r HEAD^ &&
+ ! test_cmp_rev HEAD^2 khnum &&
+ test_cmp_graph HEAD^.. <<-\EOF &&
+ * Merge branch '\''khnum'\'' into asherah
+ |\
+ | * yama
+ o shamkat
+ EOF
+ test_tick &&
+ git rebase --rebase-merges=rebase-cousins HEAD^ &&
+ test_cmp_graph HEAD^.. <<-\EOF
+ * Merge branch '\''khnum'\'' into asherah
+ |\
+ | * yama
+ |/
+ o shamkat
+ EOF
+'
+
+test_expect_success 'labels that are object IDs are rewritten' '
+ git checkout -b third B &&
+ test_commit I &&
+ third=$(git rev-parse HEAD) &&
+ git checkout -b labels master &&
+ git merge --no-commit third &&
+ test_tick &&
+ git commit -m "Merge commit '\''$third'\'' into labels" &&
+ echo noop >script-from-scratch &&
+ test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
+ test_tick &&
+ git rebase -i -r A &&
+ grep "^label $third-" .git/ORIGINAL-TODO &&
+ ! grep "^label $third$" .git/ORIGINAL-TODO
+'
+
test_done