Comment # 28 on bug 1094733 from Michal Srb

Thank you for the coredump and sorry for the long delay.

It is QSGAtlasTexture who is calling the glTexSubImage2D. It is trying to
upload 32x32 "TEX" icon to position 1322x86. It believes that the current
texture has size 2048x2048, but in reality it has size 956x509. It wants to
have texture with name 12 bound and that one really is bound at the moment. All
texture parameters match what the QSGAtlasTexture would set up.

I did not find any other QSGAtlasTexture or QSGPlainTexture that would have
size 956x509 or were using texture the name 12.

So we know that the right texture is bound, but unfortunately I still have no
idea how the texture got the dimensions 956x509.

Would you be willing to collect more data using the apitrace tool? It is not
packaged in openSUSE, but you can either build it from sources or get it from
my OBS home project:
https://download.opensuse.org/repositories/home:/michalsrb:/X11/openSUSE_Leap_15.0/

Please run it like this:
export APITRACE_BACKTRACE="glViewport glTex* glGenTex* glDeleteTex* glBindTex*"
apitrace trace plasmashell

Let the plasmashell run until it shows the distortion, then terminate it. It
will produce file plasmashell.trace. Please attach it.