I open a photo and try a filter.

then I decide against it and click cancel. the effect disappears.

but when I click in the photo again the same filter reappears.

sometimes I till be trying another filter, but when I click in the photo the same filter as before reappears.
if I go to tools and click on a tool, but then decide I dont want to use it, I click in the square at the top right of the tool dialogue box. the box disappears. but if I click in the image I am working on the same tool reappears.

if I go to colors>curves, make my adjustment then click off curves. If I click again in the image, the curves dialogue box reappears.

is this a malfunction?
if not, I would like to know how to disable it.

My system: Linux Mint, 20.3
GIMP 2.10.30

That is the way it works, Gimp does not have a 'neutral' tool. The last used is active.

Using your Curves example, bring up the curves dialogue, adjust cancel or ok it., the dialogue goes away. Now look at the Tool Options, Curves is still active. Choose another tool to leave 'Curves' . I always use the paint tool but for a neutral tool probably the measure tool is best.



errr...not the way to do it, you are just swapping the Tool Options dock for something else. The last used tool is still active.

thanks for this

so, it isn't possible just to have no tool active?

Correct

If you are concerned about "inadvertent edits" use the measure tool.

I myself before and after I use a filter, I selelect the Move tool and no filter pop up again.

I usually check rectangle select after using a tool to get it off the tool just used. I never use the measure tool so dont have it in my visible list

Why will you click on an image with no filters nor tool selected? (we are speaking about the left click, right?)
I am asking this because I would like to understand, what would be the purpose to click on an image if it's to do nothing?
Or maybe you are expecting something else?