Pascal Obry

> Can that be due to so "door openings" during libraw integration? I don't think so since the API for this library is only called when no rawspeed support is...

Could it be due to this commit 60a65ac17ab45f195ed55862d4e69029e58983ec

> That's what @jandren changed and i think that's correct. I'm not saying that it is not correct, just that it may explain the difference we see between 3.8 &...

4.0 with https://github.com/darktable-org/darktable/commit/60a65ac17ab45f195ed55862d4e69029e58983ec reverted:  (close to what we had in 3.4).

And the OP picture with https://github.com/darktable-org/darktable/commit/60a65ac17ab45f195ed55862d4e69029e58983ec reverted: 

@dterrahe : Even if a bug fix I'm wondering if this is safe for 4.0.1? Looks like a bit invasive. How do you feel?

@dterrahe : Noted, waiting for wpferguson feedback on #12338.

@ralfbrown : This is a performance related PR. Maybe you want to review? I have planned this for 4.0.1, all please let me know if ok or if you see...

BTW, this was motivated after having handled more than 200 pictures yesterday. For the first time I have applied a simple local contrast preset using `diffuse & sharpen` and it...

@ralfbrown : I still think that diffuse module being slow it should honor the fast-pipe mode and do nothing. Don't you think?