Re: re-search-forward ... nil t) results in error instead of returning nil

[Stefan Monnier]

> (re-search-forward "\"\\(?:[^\\\"]\\|\\\\\\(?:.\\|[\n]\\)\\)*\"\\|`[^']+'"
[...]
> Debugger entered--Lisp error: (error "Stack overflow in regexp matcher")
[...]
> BTW (probably unrelated to bug): In Emacs 20, doing the same thing,
> but using this similar regexp (no non-greedy matching), succeeds, with
> no Stack overflow error:
> "\"\\([^\\\"]\\|\\\\\\(.\\|[\n]\\)\\)*\"\\|`[^']+'"

The stack-overflow error depends on the text being matched.  In the present
case, the condition for this error is basically that TEXT/N > STACK where
TEXT is the number of chars in the buffer (after point), STACK is the amount
of stack space left when the function is called, and N is a constant that
depends on how the regex.c code is compiled (i.e. things like size of `int'
and pointers).  N has changed between Emacs-20 and Emacs-21, so maybe that's
the source of the problem (I can't remember if N got smaller or bigger,
tho), but a more likely situation is that TEXT was not the same in your
two tests.


        Stefan