Using styles on export

Hej, not sure if this question was already discussed, but I have a question regarding the use of styles on export.

I recognised, that when copying a module via history stack from one picture to another , where this module is already active, the previous settings get overwritten by the copied stack.
So I wonder, how to proceed, when I want to add another instance of sharpening on export, when resizing images.

Will the original sharpening settings simply be overwritten? Or are they added, like when one manually create new instances of a existing module?

If I am not wrong, when you apply the stack you can choose to ‘overwrite’ or ‘append’. Just look closer at the ‘module’ that handles the stack, there are some drop down boxes there that let you choose how you want to do it.

Here is the link from the manual: https://www.darktable.org/usermanual/en/history_stack.html

At export time the style is always appended on top of the current history.

I know, but at least in my version this doesn’t work as I expect. E. g. when picture A has two instances of sharpening (non-numbered and number 1) and I copy instance 1 to picture B, which also has a non-numbered instance active. Then the non-numbered instance of picture B is overwritten with copied instance 1. Which means, that in the end only one instance of sharpening is present.

Having two instances of the same module only works, if I create a new instance in the developing mode manually.

I’m lost! Now your are speaking of copy of history whereas your original questions was about style at export time.

I think that from the first post it is quite clear that @aequalis wants to find out what happens when using a style for export and uses copying the history for testing purposes (since it should behave similarly).

Also, the question is about creating duplicate instance of a module in the export style. If I understand it correctly, this is not directly related to where the style is put on the history stack.

Yes, that’s indeed what I meant.

Style at export are controlled by the export mode (append or replace). When in append mode the style is ALWAYS appended at the top of the history as I already said. And this is independent of the fact there is multiple instance or not.

There is no relation with the copy history which indeed does not work the same regarding multi-instance. This is a current PR for fixing that.

And is this true regardless of the applied module? What about, if I apply a different demosaicing algorithm on export, than during developing? Is the image demosaiced twice?

No single instance modules are always replaced indeed.

Alright, thanks for the explanations!