Fix R= line handling when there is no value and improve presubmit TAG line regex

tests/git_cl_test.py

Index: tests/git_cl_test.py
diff --git a/tests/git_cl_test.py b/tests/git_cl_test.py
index a890dac4f3edad5a06db9e1f03ad3f946eba0a70..e9966ff3b49bbcefaf5165d4c071f2c0485c6942 100755
--- a/tests/git_cl_test.py
+++ b/tests/git_cl_test.py
@@ -612,11 +612,16 @@ class TestGitCl(TestCase):
       ('foo\nBUG=', ['a@c'], 'foo\nBUG=\nR=a@c'),
       ('foo\nR=xx\nTBR=yy\nR=bar', ['a@c'], 'foo\nTBR=a@c'),
       ('foo', ['a@c', 'b@c'], 'foo\n\nR=a@c, b@c'),
+      ('foo\nBar\n\nR=\nBUG=', ['c@c'], 'foo\nBar\n\nR=c@c\nBUG='),
+      ('foo\nBar\n\nR=\nBUG=\nR=', ['c@c'], 'foo\nBar\n\nR=c@c\nBUG='),

[iannucci, 2013/04/18 18:25:16]

Should there be tests to make sure that the newline-avoidance regex changes you
made WAI?

[M-A Ruel, 2013/04/19 16:58:42]

Added more checks to ensure no regression.

     ]
-    for orig, reviewers, expected in data:
+    expected = [i[2] for i in data]
+    actual = []
+    for orig, reviewers, _expected in data:
       obj = git_cl.ChangeDescription(orig)
       obj.update_reviewers(reviewers)
-      self.assertEqual(expected, obj.description)
+      actual.append(obj.description)
+    self.assertEqual(expected, actual)
 
 
 if __name__ == '__main__':