Stack overflow hitting return in long document or long comment

[zenspider]

If I have a large document, presumably with a lot of comments and I hit return after a certain number of bytes, I get the following error:

Debugger entered--Lisp error: (error "Lisp nesting exceeds `max-lisp-eval-depth'")
  #[0 blah blah blah lots of binary strings blah blah])
  syntax-ppss()
  rust-in-str-or-cmnt()
  rust-rewind-irrelevant() [... 589 times ...]
  rust-mode-indent-line()
  indent-according-to-mode()
  electric-indent-post-self-insert-function()
  self-insert-command(1)
  newline(nil 1)
  call-interactively(newline nil nil)
  command-execute(newline)

Worse, it leaves me in a very broken state and all typing appears "backwards". What is actually happening is some half-functioning macro is prepended to post-self-insert-hook that effectively runs move-beginning-of-line on every character, causing you to type on the front of the current line. To fix that, I have to M-: and paste in:

(setq post-self-insert-hook '(electric-indent-post-self-insert-function blink-paren-post-self-insert-function))

which removes the bad hook.

The problem appears to be:

(defun rust-rewind-irrelevant ()
  (let ((starting (point)))
    (skip-chars-backward "[:space:]\n")
    (if (rust-looking-back-str "*/") (backward-char))
    (if (rust-in-str-or-cmnt)
        (rust-rewind-past-str-cmnt))
    (if (/= starting (point))
        (rust-rewind-irrelevant))))

But elisp doesn't have tail-call optimization, so it blows out and doesn't clean up after itself. This function can be rewritten with a named let loop or something... or the calling function should have an unwind handler on it.

Oh... and large is ~665 lines or ~16000 chars. Not sure which of the two is relevant, but given the above stack trace, it is probably the number of lines.

[zenspider]

Thanks!