Zsh - lots of blank space upon resizing VTE based terminals

Question

Hello
I have an issue that is rendering me sleepless these days. It's about zsh and its behaviour when being run inside a VTE based terminal (e.g. gnome-terminal, xfce4-terminal, roxterm, sakura, ...).
When I increase the terminal height, if the buffer exceeds the window height, the content above won't get correctly shifted down, but simply blank space is added at the bottom.
On the contrary, when I decrease the terminal height, it does not simply remove the blank space at the bottom, but instead shifts up the buffer, keeping the blank space.
This is quite annoying, because everytime I resize my windows (which happens quite often, as I'm in a tiling WM), I find myself scrolling up in order to see older output because there's only one line remaining. And even worse, as I start typing, it all scrolls back down, even though I type within the visible area.
This does not happen upon running another shell (bash, dash), or zsh in a non-VTE terminal (urxvt, xterm), however I'd like to stay with zsh and xfce4-terminal (as I'm having lots of other issues with urxvt).
After hours of googling, I haven't found any entry about a similar problem, which I find slightly confusing, since one of my friends has exactly the same behaviour with xfce4-terminal and zsh (he just hasn't noticed until I asked him, as he doesn't resize his terminal windows that often).
My question(s):
Does anybody else use zsh in a VTE-based terminal? And if so, do you get the same behaviour? And if not, could you help me out with your configuration?

Answer 1

ayekat wrote:
linvinus wrote:in zsh it hardcoded,
you can check that if you run zsh inside script (script — make typescript of terminal session)
Oh, you're right. It always prints \e[J before printing a new prompt. I suppose this is due to the 'suggestions-below-the-prompt' thing.
Thanks for the script command. I learn something new every day ^^
Now I applied the patch and it works for one half of the problem:
When I decrease the window size, it correctly eats up the blank space at the bottom (so the text no longer gets pushed upwards).
However, when I increase the window size, it still adds blank space to the bottom. So basically once a window has been sized down to, say, 10 rows, it will always stay at those 10 rows (except of course there's some new output).
i think this is normal, but may be you are right.
i will see what can be done better.
ayekat wrote:However I just saw that that I've patched the GTK2 version of VTE, perhaps it's better with the vte3 package.
no it will the same.
ayekat wrote:
... this also explains why some terminals like xfce4-terminal and lxterminal behave as described above, while others like gnome-terminal or roxterm just continue bugging.
Again, thank you!
I'll try this afternoon if it works with the vte3 package.
no problem