gVim not painting large files

[T Z]

gVim 9.0 (2022 Jun 20, compiled Mar 14 2024) on KDE Plasma 5.27.8 / X11 (Ubuntu 23.10) is showing some very weird behavior with large files. I have a file that is all plain ASCII, ~ 5million lines / 73 Mb. Here are the symptoms:

* :e completes quickly 

* scrolling the buffer one line up or one line down paints properly

* page down works properly

* page up does not paint. the visible contents of the buffer is the same as before the page up key. using the mouse to scroll up or down one line (or using arrows to move the cursor off the top or bottom) immediately paints the buffer to show the correct contents.

* forward search (/) when it jumps to a hit off the bottom of the visible buffer does not repaint. WEIRDLY it will repaint the very first character of the match. That is, /foo will find the next match on foo, correctly decide what lines would have been displayed, place the cursor on where the match would be in the to-be-drawn buffer, and then render the f but nothing else. The rest of the visible buffer remains the same. As with page up, scrolling by a single line in either direction immediately paints the buffer properly.

* n.b. when the buffer doesn't paint this includes line numbers. line numbers are correctly painted after scrolling up or down by one line.

cheers

[T Z]

For what it's worth the issue occurs with vim-gtk3 but does not occur with vim (non-graphical) of the same version. I've never seen this behavior prior to a recent upgrade to vim 9.

[Christian Brabandt]

That's weird. Can you verify using `gvim --clean`? Also please consider
testing with at least 9.1. gvim9.0 is already 2 years old.


Thanks,
Christian
--

[Christian Brabandt]

Oh and please test if :redraw! helps.

Thanks,
Christian
--
Chemistry is applied theology.
-- Augustus Stanley Owsley III