Resizing the terminal cuts off output

[STaRDoGG CHaMP]

Hi,

when I resize a urxvt terminal window, it cuts off the output of the terminal
if the borders overlap with its content. I made a video demonstrating this [1].
In the video I use i3 and I have already asked the i3 guys [2], but they told
me it's a urxvt issue. In fact I tried it with other DEs such as xfce4 for
example and the problem was present there as well. The video also shows that
this problem is not present with xterm, which makes it more likely that it is
actually a urxvt issue.

To reproduce this you can simply do the following:
- Open a new urxvt terminal window
- Create some lengthy output as in the video
- Resize the terminal window such that the borders of the window overlap with
  the output

As a result, the overlapping portion will be cut off. If you use a tiling
window manager this becomes quite an annoyance since terminal windows will be
resized more often than in a non tiling window manager.

Best

[1] https://vid.me/IdNG
[2] https://faq.i3wm.org/question/6989/resize-issue-with-urxvt/