User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0

Steps to reproduce:

Turn on apz.allow_zooming in about:config. Zoom in using pinch-to-zoom on precision touchpad or using ctrl + +. After it try to zoom out and back to previous zoom level.

Actual results:

Website after zooming is not in "normal" (100%) zoom level.

Expected results:

Website should back to 100% zoom level.

(In reply to Piotr from comment #0)

Zoom in using pinch-to-zoom on precision touchpad or using ctrl + +.

"Pinch-to-zoom on touchpad" and "ctrl+plus" do different things with apz.allow_zooming=true: the former only scales (the new feature enabled by apz.allow_zooming), while the latter scales and reflows. You probably don't want to be mixing them.

Website after zooming is not in "normal" (100%) zoom level.

Do you mean it's at a smaller zoom level than 100%?

Can you get to the smaller zoom level from the initial state by pinch-zooming out?

Can you give an example site where this happens?

Do you mean it's at a smaller zoom level than 100%?
It's bigger than should be.
Can you get to the smaller zoom level from the initial state by pinch-zooming out?
Yes, and again, if I zoom it to 100% level, website still is in bigger state.

I recorded a video to better describe the issue: https://streamable.com/djn4b
On the video, I'm zooming using pinch-to-zoom on touchpad.

Ah, right. On Windows, APZ zooming is not hooked up to touchpads yet, only touchscreens. As a result, the pinch gesture shown in the video is still performing the old-style reflowing zoom.

Supporting Windows touchpads is tracked in bug 1568676.