HTML with inline script can cause an error in mhtml-syntax-propertize.
Recipe from emacs -Q: Visit a new file "index.html" and insert these
contents:
<html>
<head>
<script> 0 </script>
</head>
<body>
it's
</body>
</html>
Put the cursor after the zero and type a semicolon. An error is signalled.
(Note the "unmatched" apostrophe in the HTML body.)
Errors:
Error during redisplay: (jit-lock-function 1) signaled
(wrong-type-argument number-or-marker-p nil)
mhtml-syntax-propertize: Wrong type argument: number-or-marker-p, nil
Backtrace:
Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil)
sgml--syntax-propertize-ppss(86)
mhtml-syntax-propertize(33 107)
syntax-propertize(50)
syntax-ppss()
electric-indent-post-self-insert-function()
self-insert-command(1 59)
funcall-interactively(self-insert-command 1 59)
call-interactively(self-insert-command nil nil)
command-execute(self-insert-command)