Problems with multi-select

Multi-selecting photos causes strange behavior when switching between photos (might cause other problems too).

1. Create a project with 4 photos (e.g. copies of "a.png", named "a.png", "b.png", "c.png", "d.png" -- "A", "B", "C", "D" for short -- mark them as clearly different, such as using all 4 rotations, or "writing" the letters on them using brush).
2. In the photo list, click "D". "D" is shown in the main viewport, "D" is highlighted as selected in the list, navigation buttons (First/Previous/Next/Last) below the viewport are on/on/off/off, as expected.
3. In the photo list, Ctrl+click "B". "D" is still being shown in the main viewport, "B" and "D" are highlighted as selected in the list, navigation buttons are still on/on/off/off, everything probably as expected. (It would be also okay (possibly better? not sure), if "B" was shown and the buttons were on/on/on/on.)
4. Click the "Previous" navigation button. Unexpectedly, "D" is still being shown, (only) "C" is highlighted in the list, and the navigation buttons are now on/on/on/on.
5. Click "Previous" again. Unexpectedly, nothing seems to happen. (Step 5 can be repeated, nothing happens.)
6. Click "First". Unexpectedly, "D" is still being shown, (only) "A" is highlighted, navigation buttons are off/off/on/on.
7. Click "Next". Unexpectedly, "D" is still being shown, (only) "D" is highlighted, navigation buttons are on/on/off/off.

(Similarly strange behavior occurs when "B" is selected first, and "D" selection is added second. I haven't checked which photo actually gets edited in these states -- the one that is displayed? Another one? More than one?)