ZSH vertical resize - last terminal line disappears

ZSH vertical resize - last terminal line disappears

[Florian Meier]

Hi folks!

I've notices a weird thing, when using a two line zsh prompt, maybe
you can help me.

Every time I split my terminal vertically (or just resize it), the
last line of the text output disappears or just gets overwritten by
the prompt, I don't know.
I made a video for you guys to better understand my problem:
http://sendvid.com/i9uw32d8
Please notice, that the last line of the first 'ls', which is the zsh
symlink, disappears after the split.

To better reproduce the problem, I recorded the video on a fresh
ubuntu 15.10 installation with a default zsh config and the adam2
theme.

The same problem happened to me with my custom prompt on different
window managers, terminal emulators and even $TERM variables.

Thank you in advance!

Regards
Florian

Re: ZSH vertical resize - last terminal line disappears

[Florian Meier]

Hi guys

As a follow-up, i found a workaround by accident.
When the first line (the "-----------" line) does not reach the column
on the very right, the problem disappears...
Is someone able to reproduce this weird behavior?

Regards
Florian


On 9 February 2016 at 20:13, Florian Meier <flmeier90@gmail.com> wrote:
> Hi folks!
>
> I've notices a weird thing, when using a two line zsh prompt, maybe
> you can help me.
>
> Every time I split my terminal vertically (or just resize it), the
> last line of the text output disappears or just gets overwritten by
> the prompt, I don't know.
> I made a video for you guys to better understand my problem:
> http://sendvid.com/i9uw32d8
> Please notice, that the last line of the first 'ls', which is the zsh
> symlink, disappears after the split.
>
> To better reproduce the problem, I recorded the video on a fresh
> ubuntu 15.10 installation with a default zsh config and the adam2
> theme.
>
> The same problem happened to me with my custom prompt on different
> window managers, terminal emulators and even $TERM variables.
>
> Thank you in advance!
>
> Regards
> Florian

Re: ZSH vertical resize - last terminal line disappears

[Bart Schaefer]

On Feb 9,  8:13pm, Florian Meier wrote:
} 
} Every time I split my terminal vertically (or just resize it), the
} last line of the text output disappears or just gets overwritten by
} the prompt, I don't know.


On Feb 10,  4:40pm, Florian Meier wrote:
}
} As a follow-up, i found a workaround by accident.
} When the first line (the "-----------" line) does not reach the column
} on the very right, the problem disappears...
} Is someone able to reproduce this weird behavior?


So what's happening is that the terminal *might* scroll when a character
is printed in the bottom right corner.  This behavior depends on the
terminal type and sometimes on a configurable setting for the terminal.
Sometimes it depends on whether that last character is a space or a
newline or is followed by a newline.  There's some discussion of this
in the manual under the ZLE_RPROMPT_INDENT variable.

Depending on whether this happens or not, ZLE can get confused about
the number of lines it needs to move upward from the bottom of the
screen in order to redraw the prompt.

The difficulty is that there's no reliable way to determine how any
given terminal will behave; even when there is a corresponding terminfo
field, it is often incorrect.  No matter what we do it'll always be
wrong for somebody.  Your workaround -- avoiding lines that print all
the way to the right margin is the only 100% effective approach.

Re: ZSH vertical resize - last terminal line disappears

[Sebastian Gniazdowski]

Hello,
does this happens with bash? This could be a nice coarse-grained test
to just gather more data on this

Best regards,
Sebastian Gniazdowski

Re: ZSH vertical resize - last terminal line disappears

[Bart Schaefer]

On May 4,  7:32pm, Sebastian Gniazdowski wrote:
}
} does this happens with bash?

Bash doesn't make any attempt to redraw the prompt in real time to fit
the new window size, as far as I can tell, so it would not be a valid
test.

-- 
Barton E. Schaefer