[BUG] borderless transparency and geometry in v9.26

[zaza at sirc.hu]

Hi!

I'm using urxvt for years in transparent and borderless mode. Last year
an IceWM update broke this feature a bit, and IceWM developer made a
workararound. Unfortunately this v9.26 brought back the same little
annoying bug: black borders around until I not moved the window on the
screen. More details and screenshots at
https://github.com/bbidulock/icewm/issues/492 .
I don't know if it is a bug in IceWM or urxvt. Last year an IceWM
update broke this transparent+borderless mode, now an urxvt update did
the same.

The full command line for reproducing: 
`rxvt -bl -tr -geometry +100+50 -e top`

Screenshot: https://0x0.st/-LFB.png


zaza