Remember what branches we delete and do not try to reparent them in cleanup.

tests/git_rebase_update_test.py

Index: tests/git_rebase_update_test.py
diff --git a/tests/git_rebase_update_test.py b/tests/git_rebase_update_test.py
index 64f7fd3b7e49e03ff588061a1c6e866fcd36febf..0dea37e60b8a1ebd608f33a67021b3bbe4c77dba 100755
--- a/tests/git_rebase_update_test.py
+++ b/tests/git_rebase_update_test.py
@@ -116,6 +116,9 @@ class GitRebaseUpdateTest(git_test_utils.GitRepoReadWriteTestBase):
     output, _ = self.repo.capture_stdio(self.reup.main)
     self.assertIn('Cannot rebase-update', output)
 
+    self.repo.run(self.nb.main, ['empty_branch'])
+    self.repo.run(self.nb.main, ['--upstream_current', 'empty_branch2'])
+
     self.repo.git('checkout', 'branch_K')
 
     output, _ = self.repo.capture_stdio(self.reup.main)
@@ -126,6 +129,8 @@ class GitRebaseUpdateTest(git_test_utils.GitRepoReadWriteTestBase):
     self.assertIn('Rebasing: foobar', output)
     self.assertIn('Rebasing: sub_K', output)
     self.assertIn('Deleted branch branch_G', output)
+    self.assertIn('Deleted branch empty_branch', output)
+    self.assertIn('Deleted branch empty_branch2', output)

[agable, 2014/03/29 00:02:04]

See today's ToT: Would be better to have many smaller tests of rebase-update
that each test one feature of it (deleting empty branches, reparenting children
of deleted branches, etc.)

     self.assertIn('Reparented branch_K to track origin/master', output)
 
     self.assertSchema("""