I've posted to my ppa packages (for Ubuntu 12.04) of newer pixman and cairo with the downscaling fix, and a inkscape-trunk package built against these.
https://launchpad.net/~bryce/+archive/backports/+packages
[Installation for Ubuntu 12.04] 1. sudo apt-add repository ppa:bryce/backports 2. sudo apt-get update 3. sudo apt-get install inkscape-trunk # This will also pull in and install newer cairo and pixman 4. /usr/bin/inkscape
[Test Case] I've verified this fixes the bug, using the following test case:
1. Draw some horizontal, vertical, and other angled lines, black stroked, 1 unit wide. 2. Export selection to PNG. 3. Delete the drawn lines from Inkscape 4. Import the PNG we just created, embedded. 5. Drag the upper right corner to resize the embedded PNG
Broken Behavior: The lines will blink in and out irregularly as you scale the image down; at a certain small scale the whole image will vanish.
Fixed Behavior: The lines shrink in size quite smoothly, becoming fainter and fainter grey until you hit a scale that they fade out completely.
The pixman package is simply the current Ubuntu 13.10 package (release 0.30.2), rebuilt for 12.04 with no changes. The cairo package is the current Ubuntu package (release 0.12.16), with the downscaling patch applied via the packaging. The inkscape package is just today's snapshot I took from the Inkscape Trunk ppa, with the cairo version requirement changed in debian/control so that it will pull in
Have I missed anything? If no one raises an objection, I will upload the pixman and cairo packages to the Inkscape trunk and stable PPAs for Ubuntu 12.04, 12.10, 13.04, and 13.10, and commit the debian/control dependency version change to trunk. I believe that should appropriately solve this bug for all Ubuntu users.
Bryce