Re: error upon load and tab navigation [PATCH included]

[Katsumi Yamaoka <yamaoka@xxxxxxx>]

In [emacs-w3m : No.12732]
On Mon, 10 Jul 2017 01:36:43 -0400, Boruch Baum wrote:

> 1] For I don't know how long, I've been getting the following errors
>    logged to my *Messages* buffer when loading emacs-w3m via M-x w3m,
>    and when tabbing through links / forms / images on a page.

>   #+BEGIN_SRC conf
>   w3m-replace-in-string: Wrong type argument:
>   arrayp, nil Error in post-command-hook (w3m-check-current-position):
>   (wrong-type-argument arrayp nil)
>   #+END_SRC

`w3m-check-current-position' runs `w3m-after-cursor-move-hook'
in which these functions are listed by default:

w3m-highlight-current-anchor
w3m-show-form-hint
w3m-print-this-url
w3m-auto-show

Is it possible to know what function calls `w3m-replace-in-string'
with a non-string argument?  Well, I think the following function
definition will reveal it if `debug-on-error' is t.

(defun w3m-replace-in-string  (string regexp newtext &optional literal)
  (or regexp newtext string (error "XXX"))
  (replace-regexp-in-string regexp newtext string nil literal))

> 2] In the attached patch, please notice that I also removed a check
>    for the existence of function `replace-regexp-in-string' and
>    removed an option to alias a command to function
>    `replace-in-string'.

Emacs-w3m hasn't officially dropped the XEmacs support yet, so
we cannot remove `replace-in-string'.

xemacs-21.4.24 -batch -q -eval\
'(message "%s" (fboundp (quote replace-regexp-in-string)))'
 => nil

>    My guess is that code was written at some point in the ancient past
>    before `replace-regexp-in-string' became a standard part of emacs,
>    and when there did exist a function called `replace-in-string'.
>    That hasn't been the case since at least four years[1].

That's right.  Emacs-w3m followed in Gnus' foot steps.  But Gnus
dropped the XEmacs support and `gnus-replace-in-string' was marked
obsolete in Emacs 26.  I have no objection on dropping it even if
I have a nostalgia on XEmacs (the tab-browsing feature of emacs-w3m
has started with XEmacs ;-).

> 3] There are several cases similar to #2 above in `w3m-util.el' for
>    which I'd be happy to provide patches if you agree that this is
>    desirable. Some examples:

Before staring those works, we have to decide what versions of
Emacs (and XEmacs, SXEmacs ...) that emacs-w3m should support.

Regards,