0.98.4 (and older): Window randomly resizes itself on macOS

[Hamuko]

XnView: 0.98.4 64bits (May 28 2021) (but has been happening for a while now)
OS: macOS 10.14.6 (18G103)

Effect: Sometimes when using XnView MP, the window randomly resizes itself on the X axis, going beyond my desktop's frame.

Screenshot 2021-06-22 at 20.54.33.png

Normally my window is 2560 pixels wide, so taking up the full display space on a 2560x1440 display.

Screenshot 2021-06-22 at 21.05.22.png

However, when this bug occurs, it takes on a pretty wild and random resolution, like so:

Screenshot 2021-06-22 at 20.54.28.png

In this instance, the window is 3928 pixels wide (1.53x). However, this does not seem to be consistent - another reproduction yielded a window that was 4061 pixels wide (1.59x).

I do not know a good way to reliably reproduce this issue, but it does happen to me daily. I usually keep XnView MP on a secondary virtual desktop and switch to it when I need to use it. I also don't exit out of the application unless this bug occurs, so it might also be related to uptime.

However, when it happens, it keeps happening on a very regular basis whenever opening an image from the browser, browsing through images or deleting images in the viewer mode. I can resize the window back to its normal size, scroll through the images for a few seconds rapidly and it's almost certainly gone beyond the screen borders again. The remedy is to relaunch the application, which usually keeps it working for at least a little bit.

One issue that I've speculated about is the fact that I'm running two monitors - on the left side of the monitor with XnView MP I have another monitor with an identical resolution.

This also appears to be a macOS-exclusive issue - I use the same dual-monitor display on my Windows 10 PC as well and I have never observed XnView MP exhibiting this issue there.

[xnview]

you have this problem when opening a new image from Finder?

[Hamuko]

No, I never open XnView from Finder. Really the only Finder integration I use is "Open in Finder" on directories.

Usually it starts to happen when I double-click an image open in the browser, or I move between images in the viewer, either by going forwards/backwards with the arrow keys, or deleting the current image I'm on.

[Hamuko]

Another thing that I've noticed when this starts happening is that my mouse wheel changes its function. I have mouse wheel set to scroll up/down and mouse wheel + CTRL set to zoom in/out. However, when this resizing bug occurs, using the mouse wheel changes to be zoom in/out.