*Affects*: version 26 (git-bisected to commit 8e7712c7afc)

Note: I have only tried this on --without-x emacs

*Steps to reproduce*

   1. start emacs
   2. start a term buffer with M-x term
   3. run `seq 1000` at the bash prompt to fill the screen
   4. enlarge the terminal window that emacs is running in, so that the
   window size changes as well
   5. run `seq 1000` again, and observe that the new space at the bottom of
   the buffer is not being used

*Analysis notes*

term-mode *does* pick up changes after more explicit window configurations,
like splits; my workaround for months has been to split and join the
terminal window whenever I've resized it.

As best I can tell, term-mode subscribes to window size changes by adding
advice to the window-adjust-process-window-size-function variable, and the
8e7712c7afc reduced the set of situations in which that function is called.

I've developed a more automated workaround with a term-load-hook of this
form:

(add-hook 'window-size-change-functions (lambda (_frame)
(window--adjust-process-windows)))

It might be that adding this line to the term-mode setup steps would be
sufficient, but I'm not familiar enough with the window.el code to have a
guess whether that's actually a good approach.

Gary Fredericks