Styles: Append not working with hierarchical instance names

Is there an existing issue for this?

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

Describe the bug

Assume for an image, a module instance named "category1|preset1" is already present and active.
There is also a style containing the same module, but with an instance name "category1|preset2" (and completely different settings). This style shall be applied to the image with the "append" mode.
As a result, the initial instance with preset1 is overwritten/replaced with preset2.
However, if the instance "category1|preset1" is renamed to "preset1" before applying the style, the result are two instances of the module.
To my understanding, the designed behavior is that instances get overwritten by the style if they have the same name.
It seems, though, that for instances with names containing a |, only the first part of the name is taken for comparison with the already present instances.

Steps to reproduce

As an example, use the D&S module. Create two styles, one with an instance of the preset "artistic effects|bloom", one with "artistic effects|simulate line drawing".
Apply the first style to an image, switch mode to "append" and apply the second style.
Check in darkroom.

Expected behavior

darktable should take the complete instance name into account.

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

self compiled

darktable version

8b6ade32f6

What OS are you using?

Linux

What is the version of your OS?

Linux Mint 21.1 Cinnamon

Describe your system

No response

Are you using OpenCL GPU in darktable?

None

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

No source file or test is named. Reproduce the issue in darkroom with D&S styles named “artistic effects|bloom” and “artistic effects|simulate line drawing,” then trace the append behavior for module instance matching. Done means applying both styles preserves two distinct instances with their complete hierarchical names.