patch 8.2.3630: printf() with %S does not handle multi-byte correctly Commit: https://github.com/vim/vim/commit/d85fccdfed58108c4e0958d0b17c64690b5f073f Author: presuku <presuku@users.noreply.github.com> Date: Sat Nov 20 19:38:31 2021 +0000 patch 8.2.3630: printf() with %S does not handle multi-byte correctly Problem: Printf() with %S does not handle multi-byte correctly. Solution: Count cells instead of bytes. (closes https://github.com/vim/vim/issues/9169, closes https://github.com/vim/vim/issues/7486)

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