Rotation of image such that the result is taller than the window size produces inconsistent results
In Fedora we have an openQA test of Loupe, based on our previous EOG test. It runs in a VM at 1024x768 resolution and uses a test image file that is 1024x683.
One test involves opening this image in a Loupe fullscreen window, then rotating it left. I'm not sure if the image can be displayed without scaling or cropping before rotation - I'm not sure whether the window is 683 pixels tall - but it definitely can't be displayed without cropping or scaling after rotation, because the window can't be 1024 pixels tall.
This test is frequently failing because Loupe never seems to display the image quite the same way twice, when asked to rotate like this. So far we've created four 'needles' (screenshot matches) for this state, and the test still failed today because the result didn't match any of them. Here are the four needles we've created so far:
and here's today's state:
As you can see, none of them is the same, despite being produced by the exact same test procedure each time.