bug#21110: 25.0.50; Images viewed with Image[Imagemagick] mode are garbled

[Robert Marshall <robert@capuchin.co.uk>]

Eli Zaretskii writes:
 > > Date: Thu, 23 Jul 2015 11:01:20 +0100
 > > From: Robert Marshall <robert@capuchin.co.uk>
 > > Cc: 21110@debbugs.gnu.org
 > > 
 > > I can confirm that building without Cairo stops the corruption
 > 
 > If you can afford one more test, perhaps try building with Cairo, but
 > without Imagemagick (and with the rest of image support libraries).
 > The Cairo build makes quite a bit of difference in image.c, but only
 > one of them is related to the Imagemagick part, so I think it's
 > important to understand whether this issue with Cairo is specific to
 > Imagemagick or to images in general.
 > 
I did a

./configure --without-imagemagick --with-cairo

and build and with that version graphic files are no longer garbled

(It would be good IMHO if the INSTALL file mentioned the
--without-imagemagick option alongside the --without-jpeg options
rather than my having to dig through the configure script)

 > Does anyone else have problems with Imagemagick (or images in general)
 > in the Cairo build?
 > 
 > >  > Use "M-x customize-variable RET" to disable all Imagemagick types.
 > >  >
 > >  
 > > I tried this and disabled png support in imagemagick-enabled-types but
 > > still when I load a png the mode is reported as
 > > 
 > > 'Image[imagemagick] mode defined in ‘image-mode.el’'
 > > 
 > > which I assume means that it's still using imagemagick?
 > 
 > Probably.  Building without Imagemagick would resolve the mystery.
 > 

C-h m in a png file now gives me 'Image[png] mode defined in  image-mode.el' 

> >  > Btw, please do send a screenshot with the corrupted images, maybe
 > >  > seeing it will give more ideas.
 > >  
 > > Emailed yesterday
 > 
 > Yes, thanks.  Basically, I understand that the "image" shown by Emacs
 > contains no traces of the image itself, only some random garbage from
 > some entirely different graphics context, is that right?
 > 

Well if there is anything from the image it is well hidden!


Robert