Bug 417723

SUMMARY
I'm using lualatex to compile my documents.
I would like to use the preview feature, but got 'red' light at the end of compilation much too often.
Lualatex returns an error code when it quits, after the flashing yellow light, i have the red one at the end of the process.
What is frustrating is that lualatex produces a PDF file most of the time, kile could show a reasonnable preview from it.

STEPS TO REPRODUCE
1. create document lualatex escapes with error code 1, but output a PDF file anyway (command line for the preview: lualatex --synctex=1 --interaction=nonstopmode --shell-escape --output-directory=/tmp/kile-livepreview.HbSljY DS06.tex )
2. 
3. 

OBSERVED RESULT
No preview displayed, but a 15 pages PDF can be found in the temporary directory
a message displayed:
[Live-Preview-LuaLaTeX] terminé avec le code de sortie 1
on the bottom-right corner of the editor side, close to the livepreview icon, a red dot.

EXPECTED RESULT
As a PDF is obtained, even if errors are reported, display a preview generated from this PDF file.
Maybe a red message can be superposed, so the user can be aware of the errors as soon as it happens.
Preview should display an output as soon as something can be displayed. Nothing displayed should only happen if the processor ends with "no PDF output"

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: 5.4.17/KDE 
(available in About System)
KDE Plasma Version: 5.15.4
KDE Frameworks Version: 5.57.0
Qt Version: 5.12.6

ADDITIONAL INFORMATION
texlive 2019