With scaleviewport set to true, vnc screen (sometimes) becomes empty, and needs window scale change to be visible

[JVisi]

Are you certain it's a bug?

• [X] Yes, it looks like a bug

Are you sure this is not an issue in noVNC?

• [X] It is not a noVNC issue

Is there an existing issue for this?

• [X] I have searched existing issues, it hasn't been reported yet

Issue description

I ran into this issue, while I was developing an application that contains tabs. The vnc_screen works fine, so as the scaleviewport option. However when I changed tabs and then went back, the vnc_screen was nowhere. When I opened the devtools it reappeared.

After this I realized that setting scaleviewport attribute, it sometimes works like this. Other times it's completely normal. If the screen resolution somehow changes, for example putting the app in fullscreen mode, the vnc screen reappears.

Can I work around this?

Dynamically setting the size of the vnc_screen does not seem to solve the problem

[roerohan]

@JVisi

I wasn't able to reproduce this, could you help me by listing some steps that I should follow for reliable reproduction?