Darkroom filmstrip: the current image is auto-selected (or not) per selection type

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

Depending on how I create a selection (not including the current image), the current image will or will not be automatically added to the selection. This behavior is unexpected and has resulted in the current image being rated unexpectedly. I have probably culled images due to this issue. So I suggest the current image should always be automatically added to a selection, or never.

• the currently open image is automatically selected when you click another image
• it can be removed from the selection with ctrl+click
• it is deselected when you shift+click to make a range (unless it is part of that range)
• it stays maintains its state until a new selection is started until an image is clicked or shift+clicked, whereupon it changes state as described above
• ctrl+clicking within a range to turn it into a discontinuous selection does not cause the current image to be added to the group, no does a manually created selection range (multiple sequential ctrl+clicks) remove it.

Steps to reproduce

1. Add the following custom CSS to easily see which thumbnails are selected:

#thumbtable-filmstrip #thumb-main:selected #thumb-image {
border: 2px dashed white;
}

2. Open darkroom with the filmstrip showing.

3. Click the thumbnail of a different image, or ctrl+click to select several
   Result: the chosen thumbnails are selected, as well as the currently open image. To confirm, mouse over the selection and apply a rating via keyboard shortcut. All selected images are affected.

4. Now shift+click a thumbnail to select a range that does not include the currently open image.

5. Optionally, ctrl+click other images to add or remove from the selected group.
   Result: the currently open image is not part of the selection.

Expected behavior

The current image should never be automatically added to the selection--or if there is a need for this behavior, always.

Logfile | Screenshot | Screencast

https://github.com/user-attachments/assets/df0a1145-8590-4972-8837-aa899b5c7ba8

Commit

No response

Where did you obtain darktable from?

self compiled

darktable version

5.7.0: commit 9242e21fb plus radialmonster's two focus fixes

What OS are you using?

Windows

What is the version of your OS?

Windows 11

Describe your system

No response

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

Start by reproducing the selection behavior in the darkroom filmstrip using the listed click, ctrl+click, and shift+click cases. Trace how each selection type handles the currently open image, then ensure the behavior is consistent and verify that applying a rating affects only the intended thumbnails.