#13576: add tests about the handling of (possibly broken) condcoms.
diff --git a/Lib/_markupbase.py b/Lib/_markupbase.py
index 98b9037..2af5f1c 100644
--- a/Lib/_markupbase.py
+++ b/Lib/_markupbase.py
@@ -107,6 +107,10 @@
if decltype == "doctype":
self.handle_decl(data)
else:
+ # According to the HTML5 specs sections "8.2.4.44 Bogus
+ # comment state" and "8.2.4.45 Markup declaration open
+ # state", a comment token should be emitted.
+ # Calling unknown_decl provides more flexibility though.
self.unknown_decl(data)
return j + 1
if c in "\"'":