patch 9.0.1763: crash when passing invalid buffer to undotree() Commit: https://github.com/vim/vim/commit/ab9f2ecfd4ecaf74eeed0e5ec41355589af3ec8f Author: zeertzjq <zeertzjq@outlook.com> Date: Sun Aug 20 18:35:10 2023 +0200 patch 9.0.1763: crash when passing invalid buffer to undotree() Problem: crash when passing invalid buffer to undotree() Solution: Use get_buf_arg() instead of tv_get_buf_from_arg(). closes: #12862 closes: #12830 Signed-off-by: Christian Brabandt <cb@256bit.org> Co-authored-by: zeertzjq <zeertzjq@outlook.com>

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