bug#30544: 26.0.91; ansi-term duplicates 2 line zsh prompts any time windows change (maybe other times)

[Noam Postavsky]

Aaron Jensen <aaronjensen@gmail.com> writes:

> I guess my wondering is what is different about term.el vs iTerm.
> iTerm has similar artifacts in zsh if the width is adjusted, but not
> when the height is adjusted.
>
> AFAICT the only things they do different are they rate limit the
> setting and they prevent setting it if the size is already as it
> should be.
>
> https://github.com/gnachman/iTerm2/blob/f8a5930b5c47fa6420f423fcb33320029abdcd5b/sources/PTYTask.m#L873

Odd.  I have urxvt here, and it seems to be able to resize both width
and height without getting any duplicated prompts.  Could it be that zsh
always repaints the prompt on a resize, but term.el (and iTerm for width
adjustments) don't put point where zsh is expecting after a resize?