patch 9.0.1189: invalid memory access with folding and using "L" Commit: https://github.com/vim/vim/commit/232bdaaca98c34a99ffadf27bf6ee08be6cc8f6a Author: Bram Moolenaar <Bram@vim.org> Date: Fri Jan 13 14:17:58 2023 +0000 patch 9.0.1189: invalid memory access with folding and using "L" Problem: Invalid memory access with folding and using "L". Solution: Prevent the cursor from moving to line zero.

Test for writing and reading a file of over 100 Kbyte

1 line: "This is the start"
3001 lines: "This is the leader"
1 line: "This is the middle"
3001 lines: "This is the trailer"
1 line: "This is the end"

STARTTEST
:%d
aThis is the start
This is the leader
This is the middle
This is the trailer
This is the endkY3000p2GY3000p
:w! Xtest
:%d
:e! Xtest
:.w! test.out
3003G:.w >>test.out
6005G:.w >>test.out
:qa!
ENDTEST