Make sure Homu hidden approval command parses

Homu leaves self-approvals in comments, like

    <!-- @bors r=someone abcdef -->

and we need to make sure those still parse correctly.

homu/parse_issue_comment.py

@@ -151,7 +151,14 @@ def parse_issue_comment(username, body, sha, botname, hooks=[]):
            E.g. `['hook1', 'hook2', 'hook3']`
     """
 
-    words = list(chain.from_iterable(re.findall(r'\S+', x) for x in body.splitlines() if '@' + botname in x))  # noqa
+    botname_regex = re.compile(r'^.*(?=@' + botname + ')')
+
+    # All of the 'words' after and including the botname
+    words = list(chain.from_iterable(
+                     re.findall(r'\S+', re.sub(botname_regex, '', x))
+                 for x
+                 in body.splitlines()
+                 if '@' + botname in x))  # noqa
 
     commands = []
 

homu/tests/test_parse_issue_comment.py

@@ -52,6 +52,22 @@ def test_r_equals():
     assert command.actor == 'jill'
 
 
+def test_hidden_r_equals():
+    author = "bors"
+    body = """
+    :pushpin: Commit {0} has been approved by `jack`
+    <!-- @bors r=jack {0} -->
+    """.format(commit)
+
+    commands = parse_issue_comment(author, body, commit, "bors")
+
+    assert len(commands) == 1
+    command = commands[0]
+    assert command.action == 'approve'
+    assert command.actor == 'jack'
+    assert command.commit == commit
+
+
 def test_r_me():
     """
     Ignore r=me