[GUI emacs:term.el] Possible regression causes word wrapping to break term display in zsh

[Nicholas Ochiel <nochiel@gmail.com>]

Steps:
0. Open gui emacs in X.
1. M-x term (char mode, /bin/zsh)
2. Enter a long input that causes text to wrap at fringe.
3. Notice that point jumps irregularly.
4. Move point and attempt to edit some portion of wrapped line in terminal.
5. Notice that prompt or previous terminal output is overwritten in an
unpredictable manner.
6. Further operations on text cause unpredictable editing behaviour.
7. This occurs regardless of truncate-lines, visual-line-mode.

Reproduced with:
- Emacs 24.5.1,
- emacs-snapshot 26.0.50.2

This odd behaviour was also reported here:
1. https://github.com/syl20bnr/spacemacs/issues/5520

Possibly related:
1. http://stackoverflow.com/questions/5541622/comint-mode-inserts-line-break-every-4096-characters?rq=1
2. http://stackoverflow.com/questions/5872686/linewrap-in-gui-emacs-in-linux

--
Sincerely,
Nicholas Ochiel