#7627: MH.remove() would fail if the MH mailbox was locked;
it would call _unlock_file() and pass it a closed file object.  Noted by Rob Austein.
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index c88af06..7575ca7 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -979,6 +979,13 @@
         key0 = self._box.add(msg0)
         refmsg0 = self._box.get_message(key0)
 
+    def test_issue7627(self):
+        msg0 = mailbox.MHMessage(self._template % 0)
+        key0 = self._box.add(msg0)
+        self._box.lock()
+        self._box.remove(key0)
+        self._box.unlock()
+
     def test_pack(self):
         # Pack the contents of the mailbox
         msg0 = mailbox.MHMessage(self._template % 0)