bug#22072: Error in display-startup-screen if create-image fails

bug#22072: Error in display-startup-screen if create-image fails

[Richard Copley]

There's a mistake in the function "use-fancy-splash-screens-p" in
startup.el. It can set the local variable "image-height" to nil (if
creating an image from the fancy-splash-image-file fails), but later
it uses the value of "image-height" in an arithmetic expression, and
gives the error "Wrong type argument: number-or-marker-p, nil".

(The reason create-image has suddenly started failing for me is a
difference in my build environment. I'm trying out a build using only
stuff available from the MSYS2 package manager. I haven't noticed
any other problems so far. The create-image problem goes away if
I configure --without-imagemagick.)

In GNU Emacs 25.1.50.1 (x86_64-w64-mingw32)
 of 2015-12-02
Repository revision: 098738ff1a193ff6e6af71071461f75635d1b790
Windowing system distributor 'Microsoft Corp.', version 10.0.10586
Configured using:
 'configure --prefix /c/emacs/emacs-20151201-205551
 --disable-dependency-tracking
 --enable-locallisppath=%emacs_dir%/../site-lisp 'CFLAGS=-Og -g -ggdb''

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS NOTIFY ACL GNUTLS
LIBXML2 ZLIB TOOLKIT_SCROLL_BARS

Important settings:
  value of $LANG: ENG
  locale-coding-system: cp1252

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
display-startup-screen: Wrong type argument: number-or-marker-p, nil

Features:
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Memory information:
((conses 16 84676 9280)
 (symbols 56 19141 0)
 (miscs 48 36 128)
 (strings 32 14569 3411)
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bug#22072: Error in display-startup-screen if create-image fails

[Stephen Leake]

Richard Copley <rcopley@gmail.com> writes:

Can you test this patch:

diff --git a/lisp/startup.el b/lisp/startup.el
index 1346310..a281f86 100644
--- a/lisp/startup.el
+++ b/lisp/startup.el
@@ -1874,13 +1874,13 @@ we put it on this frame."
                  (image-type-available-p 'pbm)))
     (let ((frame (fancy-splash-frame)))
       (when frame
-	(let* ((img (create-image (fancy-splash-image-file)))
-	       (image-height (and img (cdr (image-size img nil frame))))
-	       ;; We test frame-height so that, if the frame is split
-	       ;; by displaying a warning, that doesn't cause the normal
-	       ;; splash screen to be used.
-	       (frame-height (1- (frame-height frame))))
-	  (> frame-height (+ image-height 19)))))))
+	(let ((img (create-image (fancy-splash-image-file))))
+              (image-height (and img (cdr (image-size img nil frame))))
+              ;; We test frame-height so that, if the frame is split
+              ;; by displaying a warning, that doesn't cause the normal
+              ;; splash screen to be used.
+              (frame-height (and img (1- (frame-height frame)))))
+	  (and img (> frame-height (+ image-height 19))))))))
 
-- 
-- Stephe

bug#22072: Error in display-startup-screen if create-image fails

[Richard Copley]

Thanks Stephen. More haste, less speed ... you shouldn't have changed
"let*" to "let" and the parentheses don't match. After fixing those
things, yes, doing as you suggest allows my broken Emacs to start
without the fancy image and without error.

On 2 December 2015 at 12:36, Stephen Leake
<stephen_leake@stephe-leake.org> wrote:
> Richard Copley <rcopley@gmail.com> writes:
>
> Can you test this patch:
>
> diff --git a/lisp/startup.el b/lisp/startup.el
> index 1346310..a281f86 100644
> --- a/lisp/startup.el
> +++ b/lisp/startup.el
> @@ -1874,13 +1874,13 @@ we put it on this frame."
>                   (image-type-available-p 'pbm)))
>      (let ((frame (fancy-splash-frame)))
>        (when frame
> -       (let* ((img (create-image (fancy-splash-image-file)))
> -              (image-height (and img (cdr (image-size img nil frame))))
> -              ;; We test frame-height so that, if the frame is split
> -              ;; by displaying a warning, that doesn't cause the normal
> -              ;; splash screen to be used.
> -              (frame-height (1- (frame-height frame))))
> -         (> frame-height (+ image-height 19)))))))
> +       (let ((img (create-image (fancy-splash-image-file))))
> +              (image-height (and img (cdr (image-size img nil frame))))
> +              ;; We test frame-height so that, if the frame is split
> +              ;; by displaying a warning, that doesn't cause the normal
> +              ;; splash screen to be used.
> +              (frame-height (and img (1- (frame-height frame)))))
> +         (and img (> frame-height (+ image-height 19))))))))
>
> --
> -- Stephe

bug#22072: Error in display-startup-screen if create-image fails

[Lars Ingebrigtsen]

Stephen Leake <stephen_leake@stephe-leake.org> writes:

> Richard Copley <rcopley@gmail.com> writes:
>
> Can you test this patch:

[...]

> -	(let* ((img (create-image (fancy-splash-image-file)))
> -	       (image-height (and img (cdr (image-size img nil frame))))
> -	       ;; We test frame-height so that, if the frame is split
> -	       ;; by displaying a warning, that doesn't cause the normal
> -	       ;; splash screen to be used.
> -	       (frame-height (1- (frame-height frame))))
> -	  (> frame-height (+ image-height 19)))))))
> +	(let ((img (create-image (fancy-splash-image-file))))
> +              (image-height (and img (cdr (image-size img nil frame))))
> +              ;; We test frame-height so that, if the frame is split
> +              ;; by displaying a warning, that doesn't cause the normal
> +              ;; splash screen to be used.
> +              (frame-height (and img (1- (frame-height frame)))))
> +	  (and img (> frame-height (+ image-height 19))))))))

I've now fixed this on the trunk inspired by this patch, but slightly
differently.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no