patch 8.2.1461: Vim9: string indexes are counted in bytes Commit: https://github.com/vim/vim/commit/e3c37d8ebf9dbbf210fde4a5fb28eb1f2a492a34 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Aug 15 18:39:05 2020 +0200 patch 8.2.1461: Vim9: string indexes are counted in bytes Problem: Vim9: string indexes are counted in bytes. Solution: Use character indexes. (closes https://github.com/vim/vim/issues/6574)

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