--- /dev/null
+#data
+FOO<!-- BAR -->BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- BAR -->
+| "BAZ"
+
+#data
+FOO<!-- BAR --!>BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- BAR -->
+| "BAZ"
+
+#data
+FOO<!-- BAR -- >BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- BAR -- >BAZ -->
+
+#data
+FOO<!-- BAR -- <QUX> -- MUX -->BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- BAR -- <QUX> -- MUX -->
+| "BAZ"
+
+#data
+FOO<!-- BAR -- <QUX> -- MUX --!>BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- BAR -- <QUX> -- MUX -->
+| "BAZ"
+
+#data
+FOO<!-- BAR -- <QUX> -- MUX -- >BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- BAR -- <QUX> -- MUX -- >BAZ -->
+
+#data
+FOO<!---->BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- -->
+| "BAZ"
+
+#data
+FOO<!--->BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- -->
+| "BAZ"
+
+#data
+FOO<!-->BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- -->
+| "BAZ"
+
+#data
+<?xml version="1.0">Hi
+#errors
+#document
+| <!-- ?xml version="1.0" -->
+| <html>
+| <head>
+| <body>
+| "Hi"
+
+#data
+<?xml version="1.0">
+#errors
+#document
+| <!-- ?xml version="1.0" -->
+| <html>
+| <head>
+| <body>
+
+#data
+<?xml version
+#errors
+#document
+| <!-- ?xml version -->
+| <html>
+| <head>
+| <body>
+
+#data
+FOO<!----->BAZ
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| "FOO"
+| <!-- - -->
+| "BAZ"