Immediately after the change to the devdraw process, I noticed that
libdraw apps would die immediately if started in the framing mode of
framing window managers, but not if started in floating mode and moved
there later. Recently, the fact that my port of page died every time it
was put into managed mode goaded me into finding the problem.

Page seems to be the only app to die whenever it receives SIGWINCH, but
every other libdraw app seems to do it periodically. I've added
notifyoff("sys: window size change") to my copy of page.c, which has
solved the problem here. Exactly why other apps, which don't explicitely
handle it are only sometimes affected, or why I've only noticed the
problem with libdraw apps, and only since the introduction of devdraw, I
can't say.