[Gambas-bugtracker] Bug #2213: Window object does not draw properly in gtk3 only

[bugtracker at gambaswiki.org]

http://gambaswiki.org/bugtracker/edit?object=BUG.2213&from=L21haW4-

Bruce STEERS reported a new bug.

Summary
-------

Window object does not draw properly in gtk3 only

Type             : Bug
Priority         : Medium
Gambas version   : Master
Product          : GTK+3 component


Description
-----------

Hi Ben.
To follow is a a simple app that is using libmpv (new, not very functional yet)

For some reason on starting the window does not initialise and draw correctly with gtk3
seems okay on qt and gtk2


System information
------------------

[System]
Gambas=3.15.90 (bruces-patched) (master fork)
OperatingSystem=Linux
Kernel=5.4.0-60-generic
Architecture=x86_64
Distribution=Linux Mint 20 Ulyana
Desktop=MATE
Theme=crux
Language=en_GB.UTF-8
Memory=7952M

[Libraries]
Cairo=libcairo.so.2.11600.0
Curl=libcurl.so.4.6.0
DBus=libdbus-1.so.3.19.11
GDK2=libgdk-x11-2.0.so.0.2400.32
GDK3=libgdk-3.so.0.2404.16
GStreamer=libgstreamer-1.0.so.0.1602.0
GTK+2=libgtk-x11-2.0.so.0.2400.32
GTK+3=libgtk-3.so.0.2404.16
OpenGL=libGL.so.1.7.0
Poppler=libpoppler.so.97.0.0
QT5=libQt5Core.so.5.12.8
SDL=libSDL-1.2.so.0.11.4
SQLite=libsqlite3.so.0.8.6

[Environment]
CLUTTER_BACKEND=x11
CLUTTER_IM_MODULE=ibus
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
DEFAULTS_PATH=/usr/share/gconf/mate.default.path
DESKTOP_SESSION=mate
DISPLAY=:0
EDITOR=pluma
GB_GUI=gb.gtk3
GDMSESSION=mate
GDM_LANG=en_GB
GIO_LAUNCHED_DESKTOP_FILE_PID=121056
GPG_AGENT_INFO=/run/user/1000/gnupg/S.gpg-agent:0:1
GTK_IM_MODULE=ibus
GTK_MODULES=gail:atk-bridge
GTK_OVERLAY_SCROLLING=0
HOME=<home>
LANG=en_GB.UTF-8
LANGUAGE=en_GB.UTF-8
LC_ALL=en_GB.UTF-8
LIBVIRT_DEFAULT_URI=qemu:///system
LOGNAME=<user>
MANDATORY_PATH=/usr/share/gconf/mate.mandatory.path
MATE_DESKTOP_SESSION_ID=this-is-deprecated
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
PWD=<home>
QT4_IM_MODULE=ibus
QT_ACCESSIBILITY=1
QT_AUTO_SCREEN_SCALE_FACTOR=0
QT_IM_MODULE=ibus
QT_LOGGING_RULES=*.debug=false
QT_QPA_PLATFORMTHEME=qt5ct
QT_SCALE_FACTOR=1
SESSION_MANAGER=local/<hostname>:@/tmp/.ICE-unix/1412,unix/<hostname>:/tmp/.ICE-unix/1412
SHELL=/bin/bash
SHLVL=0
SSH_AGENT_PID=1570
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
TZ=:/etc/localtime
USER=<user>
XAUTHORITY=<home>/.Xauthority
XDG_CONFIG_DIRS=/etc/xdg/xdg-mate:/etc/xdg
XDG_CURRENT_DESKTOP=MATE
XDG_DATA_DIRS=/usr/share/mate:/usr/share/mate:<home>/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
XDG_GREETER_DATA_DIR=/var/lib/lightdm-data/<user>
XDG_RUNTIME_DIR=/run/user/1000
XDG_SEAT=seat0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=mate
XDG_SESSION_ID=c1
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
XDG_SESSION_TYPE=x11
XDG_VTNR=7
XMODIFIERS=@im=ibus