Re: regexp stack overflow

[Katsumi Yamaoka <yamaoka@xxxxxxx>]

>>>>> In [emacs-w3m : No.08519] Silvio Neef wrote:

> Wow, it appears that TWiki is sending the entire page text as part of
> the URL when submitting changes to a page:

>   Debugger entered--Lisp error: (error "Stack overflow in regexp matcher")
>     string-match("\\`\\(\\([^:/?#]+\\):\\)?\\(//\\([^/?#]*\\)\\)?\\([^?#]*\\)\\(\\?\\([^#]*\\)\\)?\\(#\\(.*\\)\\)?\\'" "http://wiki/bin/preview/Main/BigWikiPage?text=---%2B%20Big%20Wiki%20Page%0D%0A%0D%0A [and so on, tens of kb of text ]
>     w3m-expand-url("http://wiki/bin/preview/Main/BigWikiPage?text= [same here]
>     w3m-fontify-anchors()
>     w3m-fontify()
>     w3m-create-text-page("http://wiki/bin/preview/Main/BigWikiPage"; "text/html" "ISO-8859-1" #<buffer *w3m*>)
>     ...

Oh, I see.  I could reproduce the same error using Emacs 22.0.50
and:

(progn
  (w3m-expand-url (concat "http://www.example.com/";
			  (make-string 66633 ?i)
			  "ndex.html"))
  nil)

> so wherever W3M-URL-COMPONENTS-REGEXP is used I get in trouble. One
> could probably re-write this code so that it doesn't use a regexp.

Yes, I'm sure I can solve it in some way.  I'll try it.

> However, maybe it's just a problem with my particular emacs version
> (21.2.1) or even the text I'm trying to match:

> http://lists.gnu.org/archive/html/emacs-pretest-bug/2004-11/msg00385.html

No, what have to be improved is emacs-w3m.  Thank you for
digging it out.

> For now, I just added this nasty kludge, which works only for me of
> course:

> (defun w3m-expand-url (url &optional base)
>   "Convert URL to the absolute address, and canonicalize it."
>   (if (and (> (length url) 23)
> 	   (string= (substring url 0 23)
> 		    "http://wiki/bin/preview";))
>       url
>       (progn

>       [ original function body goes here ]

>       ))

;-)