:terminal + TUI: Redraw bug when resizing

[glacambre]

• nvim --version: NVIM v0.2.1-1124-g739bc5124
• Operating system/version: Linux 4.12.12-gentoo
• Terminal name/version: rxvt-unicode (urxvt) v9.21/XTerm(327)/alacritty 0.1.0
• $TERM: rxvt-unicode-256color/xterm-256color/xterm-256color

Steps to reproduce using nvim -u NORC

First, start nvim with two horizontal windows, the upper one should be a term and bottom one a regular buffer. Reset syntax highlighting, set cterm=NONE. Append a few characters to the regular buffer. You can do all of that with the following command:

echo -n "aaa" | nvim -u NONE -c "syntax reset | highlight Normal ctermfg=213 ctermbg=213 cterm=NONE | sp term://sh | wincmd j"

Then, "violently" resize your terminal emulator (the one holding the nvim tui): you should see redraw bugs on the upper line.
I can 100% trigger this bug by using i3wm and opening/closing a new window (this divides the nvim window's width by 2 and then resizes it to its previous size).

Actual behaviour

The right half of the first line of the terminal buffer won't be properly redrawn: it will be the default color of the terminal emulator rather than the color set using the highlight Normal command.
Please note that the bug won't be triggered if the cursor is not in the normal buffer or if it is on the first column on the normal buffer.

Expected behaviour

Everything should be the same color.

Edit: Here's a screenshot of what's happening. The upper right corner is black but it should be pink.

[justinmk]

Thanks for the clear repro!

With Terminal.app it happens but then fixes itself after ~1s.

Does CTRL-L in normal-mode work around the issue for you?

[glacambre]

Indeed, CTRL-L does fix the display on all three terminal emulators, however waiting for a few seconds doesn't.

[justinmk]

@glacambre could you try #7624 ? And also try disabling the "bce" capability in your terminfo db.

[glacambre]

Still happens for urxvt (haven't tried other terminal emulators). I may have made a mistake while testing, please let me know if I should do something differently:

$ git rev-parse HEAD
1bd78400f020d20f499d7c6e52f60762e98bff51
$ echo $TERM
rxvt-unicode-256color
$ if tput bce; then; echo enabled; else; echo disabled; fi
disabled
$ echo -n "aaa" | build/bin/nvim -u NONE -c "syntax reset | highlight Normal ctermfg=213 ctermbg=213 cterm=NONE | sp term://sh | wincmd j"

[justinmk]

@glacambre Thanks. If bce is already disabled then #7624 won't make a difference. Good to rule that out.

[glacambre]

I can still reproduce this on kitty+nvim 3.1 but I can't anymore with kitty+nvim 3.2 so I assume this is fixed, probably by 1adb01c . Thanks @bfredl !