bug#14567: Scrolling of large images

[Eli Zaretskii]

> From: Thomas Wiecki <thomas.wiecki@gmail.com>
> Date: Thu, 6 Jun 2013 13:16:43 -0400
> Cc: 14567@debbugs.gnu.org
> 
> 1. Download a large image (e.g.
> http://cdn.urbanislandz.com/wp-content/uploads/2011/10/MMSposter-large.jpg)
> and save it as /tmp/test.jpg
> 2. In an emacs buffer type "(insert-image (create-image "/tmp/test.jpg"))"
> 3. Type some arbitrary lines of text below this line.
> 4. In first line (containing insert-image), type C-x C-e at end of line to
> load the image.
> 5. Image should appear in buffer.
> 6. Scroll down repeatedly until past the image.
> 
> Expected behavior: Scrolls down smoothly even once scrolled past image.
> Observed behavior: Scrolls down smoothly until end of image is reached. At
> end of image, the next scroll causes a huge jump in the window so that and
> only the text is shown but not any of the residual image.
> 
> 7. scroll back up
> 
> Expected behavior: Scrolls upwards over image.
> Observed behavior: Jumps over complete image and shows beginning of buffer.

Perfect, thanks.  I will take a look.