patch 9.0.1617: charidx() result is not consistent with byteidx() Commit: https://github.com/vim/vim/commit/577922b917e48285a7a312daf7b5bbc6e272939c Author: Yegappan Lakshmanan <yegappan@yahoo.com> Date: Thu Jun 8 17:09:45 2023 +0100 patch 9.0.1617: charidx() result is not consistent with byteidx() Problem: charidx() and utf16idx() result is not consistent with byteidx(). Solution: When the index is equal to the length of the text return the lenght of the text instead of -1. (Yegappan Lakshmanan, closes #12503)

# Clang 12 (or Apple clang 13) and later makes a warning '-Wcompound-token-split-by-macro' enable by default.
/^PERL_CFLAGS_EXTRA[[:blank:]]*=/s/$/ -Wno-error=compound-token-split-by-macro/
/^RUBY_CFLAGS_EXTRA[[:blank:]]*=/s/$/ -Wno-error=compound-token-split-by-macro/