patch 9.0.0101: invalid memory access in diff mode with "dp" and undo Commit: https://github.com/vim/vim/commit/4e677b9c40ccbc5f090971b31dc2fe07bf05541d Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jul 28 18:44:27 2022 +0100 patch 9.0.0101: invalid memory access in diff mode with "dp" and undo Problem: Invalid memory access in diff mode with "dp" and undo. Solution: Make sure the line number does not go below one.

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