bug#4030: forward-sexp parses character literal ?; as comment

[martin rudalics]

> It seems that forward-sexp (and its underlying C implementation) does
> not cope correctly with a character literal semicolon, seeing instead
> (effectively) end of line.
>
> In the *scratch* buffer if you write (insert ?;) you can evaluate this
> Lisp code and it behaves as intended (inserts a semicolon in the current
> buffer) but doing M-x forward-sexp just before the expression results in
> an "Unbalanced parentheses" error.

A similar thing happens with (insert ?") so why don't you escape such a
character by writing (insert ?\;) instead?  From the Elisp manual:

    You can use the same syntax for punctuation characters, but it is
 often a good idea to add a `\' so that the Emacs commands for editing
 Lisp code don't get confused.  For example, `?\(' is the way to write
 the open-paren character.  If the character is `\', you _must_ use a
 second `\' to quote it: `?\\'.

martin