bug#2435: Bug 2435

[Stefan Monnier]

> It will fix the current problem of bufp contents being
> changed by recursive call, but we still have a danger of
> Lisp code being called in re_compile_pattern, which may lead
> to relocation of string data pointed by the arg "pattern".
> So, I think we must avoid any Lisp calls within
> re_compile_pattern.

Indeed, tho it's not clear how we could do that.  One way that occurs to
me is: if we need to `load' or do some such dangerous operation in
re_compile_pattern, signal an error so we exit re_compile_pattern.
Then catch this error in the calling code where we can do the
corresponding operation safely and call re_compile_pattern again.
Kind of ugly, but for autoload-style operations it seems acceptable.


        Stefan