[client] fix some renderer bugs which cause SPICE display corruption #2518

Job	Run time
docs	36s
host-linux	32s
client (gcc, g++, xdg-shell, Release)	52s
client (gcc, g++, xdg-shell, Debug)	49s
host-windows-native	1m 33s
client (gcc, g++, libdecor, Release)	50s
host-windows-cross	49s
module	15s
client (gcc, g++, libdecor, Debug)	1m 11s
client (clang, clang++, xdg-shell, Release)	1m 7s
obs (gcc)	28s
client (clang, clang++, xdg-shell, Debug)	53s
client (clang, clang++, libdecor, Release)	1m 0s
client (clang, clang++, libdecor, Debug)	1m 12s
obs (clang)	32s
	12m 39s

Provide feedback