Re: Problem running gnus when image is not already loaded

Re: Problem running gnus when image is not already loaded

[Reiner Steib]

On Sat, Feb 02 2008, Harald Hanche-Olsen wrote:

> Gnus v5.11
> GNU Emacs 23.0.0.2 (i386-unknown-freebsd5.3, X toolkit, Xaw3d scroll bars)
>  of 2005-10-18 on shuttle

When running some CVS snapshot (as 23.0.0 indicates, though I don't
know to which date and branch it belongs), it doesn't make sense to
run a version more than 2 years old.

However, I think you analysis is correct nevertheless.  :-)

> The ultrashort summary:
>
> I usually read usenet news by running:  emacs -f gnus &
> from an xterm.  Once in a rare while, gnus stops with the splash
> screen still up, and the message
>
>   Symbol's value as variable is void: image-load-path
>
> in the minibuffer.
>
> I believe I have narrowed this down to the following code in
> gnus-group-startup-message (irrelevant bits brutally snipped):
>
>   (cond
>    ((and
>      (fboundp 'find-image)
>      (display-graphic-p)
>      (let* ((data-directory ...)
> 	    (image-load-path ...)
> 	    (image (find-image ...)))
>        (when image ...)))))
>
> Assume that image.el[c] has not yet been loaded when this runs.
> Now find-image is autoloaded, so the symbol is fbound.
> We bind image-load-path and call find-image, which tries to
> (defvar load-image-path)
> and that fails because the variable is let-bound.
> Of course gnus-group-startup-message succeeds, but later on
> gnus-mode-line-buffer-identification fails when it tries to put a
> little gnu in the modeline and image-load-path is unbound.
>
> I believe one needs an extra test to be run just after
> (display-graphic-p) in the code above.  Perhaps (require 'image nil t)
> would do, but we don't really want to hard code the location of
> find-image in gnus code?  So I came up with this instead
>
>      (let ((f (symbol-function 'find-image)))
>        (if (consp f)
> 	   (and (eql (car f) 'autoload)
> 		(load (cadr f) nil nil nil t))
> 	 t))
>
> but I'll leave that judgement up to you folks (obviously).

I'm not sure if your or my suggestion (force loading it by adding a
dummy call to `find-image' is preferable.  Opinions?

--8<---------------cut here---------------start------------->8---
--- gnus.el.~7.77.~	2008-01-20 10:27:58.000000000 +0100
+++ gnus.el	2008-02-02 14:21:34.000000000 +0100
@@ -1002,6 +1002,12 @@
   (cond
    ((and
      (fboundp 'find-image)
+     (or
+      ;; Make sure the library defining `image-load-path' is loaded now
+      ;; (`find-image' is autoloaded).  Else, we may get "defvar ignored
+      ;; because image-load-path is let-bound".
+      (find-image '(nil (:type xpm :file "gnus.xpm")))
+      t)
      (display-graphic-p)
      (let* ((data-directory (nnheader-find-etc-directory "images/gnus"))
 	    (image-load-path (cond (data-directory
--8<---------------cut here---------------end--------------->8---

> I have no idea why image is usually, but not always, loaded before
> gnus starts up.  Maybe if I didn't have (tool-bar-mode 0) in my
> .emacs, image would always be loaded.  But I do.
>
> Finally, for your delectation, here is a bit of the hard evidence that
> led me to the conjecture above (the other evidence is from browsing
> source code).  It is a diff between the *Messages* buffer from two
> runs of emacs -f gnus, the first one (marked -) when all is good, and
> the other (marked +) when the bug bit me.
>
> --- gnus-image-load-path-ok	Fri Jan 18 19:20:26 2008
> +++ gnus-image-load-path-not-ok	Sat Feb  2 09:39:32 2008
> @@ -12,21 +12,18 @@
>  Loading tool-bar...done
>  Loading help-fns...done
>  Loading advice...done
> -Loading image...done
> -For information about the GNU Project and its goals, type C-h C-p.
>  Loading gnus...
>  Loading fix-gnus (source)...done
>  Loading gnus...done
>  Loading gnus-start...
>  Loading easymenu...done
>  Loading gnus-start...done
> +Loading image...
> +Warning: defvar ignored because image-load-path is let-bound
> +Loading image...done
>  Loading gnus-agent...
>  Loading fix-gnus-group (source)...done
>  Loading regexp-opt...done
>  Loading gnus-agent...done
>  Reading /local/home/hanche/.newsrc.eld...
> -Reading active file from localhost via nntp...
> -Loading timezone...done
> -No new newsgroups
> -Checking new news...done
> +gnus-mode-line-buffer-identification: Symbol's value as variable is void: image-load-path
>
> - Harald
>
> PS.  I'd appreciate if you Cc'd me on any discussion of this problemm
> on your mailing list.

Done.  Added ding@gnus, MFT set.

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/

Re: Problem running gnus when image is not already loaded

[Harald Hanche-Olsen]

+ Reiner Steib <reinersteib+gmane@imap.cc>:

> When running some CVS snapshot (as 23.0.0 indicates, though I don't
> know to which date and branch it belongs), it doesn't make sense to
> run a version more than 2 years old.

Agreed, sort of.  Which is why I upgraded my sources and started a new
build around the time I sent my report.  As to why I am doing this, I
found the non-unicode emacsen too painful to use, and the
emacs-unicode-2 branch such a huge advance, I didn't mind using the
so-called "unstable" code.  As it has turned out, it has been much too
stable!  So I was never really motivated to keep tracking the CVS
source.  In fact, I believe I have seen fewer crashes with this two
year old CVS emacs than I ever did with most official emacs releases.

> However, I think you analysis is correct nevertheless.  :-)

Good to hear that.

- Harald

Re: Problem running gnus when image is not already loaded

[Reiner Steib]

On Sat, Feb 02 2008, Harald Hanche-Olsen wrote:

> + Reiner Steib <reinersteib+gmane@imap.cc>:
>> When running some CVS snapshot (as 23.0.0 indicates, though I don't
>> know to which date and branch it belongs), it doesn't make sense to
>> run a version more than 2 years old.
>
> Agreed, sort of.  Which is why I upgraded my sources and started a new
> build around the time I sent my report.  

FYI: the unicode branch has been merged to the Emacs trunk in CVS
yesterday.

> As to why I am doing this, I found the non-unicode emacsen too
> painful to use, and the emacs-unicode-2 branch such a huge advance,
> I didn't mind using the so-called "unstable" code.

I can't find Emacs 22 (or even 21) painful to use, YMMV.  But we are
getting off-topic, I think.

> In fact, I believe I have seen fewer crashes with this two year old
> CVS emacs than I ever did with most official emacs releases.

If you didn't report these crashes (in the releases), the developers
can't fix them.

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/

Re: Problem running gnus when image is not already loaded

[Harald Hanche-Olsen]

I noticed just now that you put the code to force the loading of
whatever library find-image comes from before the test
(display-graphic-p).  I think it should go after, since it makes
little sense to force the loading of this library if the user is
running emacs in a terminal.

- Harald

Re: Problem running gnus when image is not already loaded

[Reiner Steib]

On Sat, Feb 02 2008, Harald Hanche-Olsen wrote:

> I noticed just now that you put the code to force the loading of
> whatever library find-image comes from before the test
> (display-graphic-p).  I think it should go after, since it makes
> little sense to force the loading of this library if the user is
> running emacs in a terminal.

Correct.  Thanks again.  I will install the following, unless someone
points out a problem or offers a better way.

--8<---------------cut here---------------start------------->8---
--- gnus.el.~7.77.~	2008-01-20 10:27:58.000000000 +0100
+++ gnus.el	2008-02-02 19:09:41.000000000 +0100
@@ -1003,6 +1003,12 @@
    ((and
      (fboundp 'find-image)
      (display-graphic-p)
+     (or
+      ;; Make sure the library defining `image-load-path' is loaded now
+      ;; (`find-image' is autoloaded).  Else, we may get "defvar ignored
+      ;; because image-load-path is let-bound".
+      (find-image '(nil (:type xpm :file "gnus.xpm")))
+      t)
      (let* ((data-directory (nnheader-find-etc-directory "images/gnus"))
 	    (image-load-path (cond (data-directory
 				    (list data-directory))
--8<---------------cut here---------------end--------------->8---

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/