I just switched my window manager and window system to Sway under
Wayland. urxvt works quite well, except for the fact that a window
redraw event is not triggered when I resize the font.

FWIW, I have set the following lines in my .Xresurces to resize the
fonts in my terminals:

    URxvt.keysym.C-M-Up:     font-size:increase
    URxvt.keysym.C-M-Down:   font-size:decrease
    URxvt.keysym.C-M-equal:  font-size:reset
    URxvt.keysym.C-M-slash:  font-size:show

I am attaching a couple of screenshots showing my issue: I launched a
TUI application (mc), in mc_normal.png. From there, either reducing
(C-M-Down) or increasing (C-M-Up) font size makes the application use
less than all of the available space, or display information off the
viewable space. In X11, the behavior was to immediately redraw the
application.

Taking the focus out and in from the window in question does trigger
the redraw.

I don't know who would be responsible for triggering a SIGWINCH, but I
guess it's not being reliably done.

Thanks!