Accept commas in unquoted attribute values.
This closes SF patch #669683.
diff --git a/Lib/test/test_sgmllib.py b/Lib/test/test_sgmllib.py
index 90ed87e..6f4454f 100644
--- a/Lib/test/test_sgmllib.py
+++ b/Lib/test/test_sgmllib.py
@@ -200,6 +200,10 @@
         self.check_events("""<a b='' c="">""", [
             ("starttag", "a", [("b", ""), ("c", "")]),
             ])
+        # Regression test for SF patch #669683.
+        self.check_events("<e a=rgb(1,2,3)>", [
+            ("starttag", "e", [("a", "rgb(1,2,3)")]),
+            ])
 
     def test_attr_funky_names(self):
         self.check_events("""<a a.b='v' c:d=v e-f=v>""", [