I am the author of libvterm (formerly libRote) which is a terminal emulator designed specifically to output to a ncurses WINDOW. The library attempts to mimic RXVT and sets $TERM accordingly. I recently added some minimalist UTF-8 code which parses common UTF-8 encodings and writes ACS chars where it makes sense.
Depending on the underlying terminal, sometimes ACS_DARROW gets rendered as ACS_BTEE. I think this is somehow related to the notes on NCURSES_NO_UTF8_ACS since the problem doesn't occur when the terminal is Linux and slightly different behavior under Screen. On all other terms I tested, the output for ACS_DARROW is a bottom-tee (ACS_BTEE). Also, I find it coincidental that "v" is the non-acs equivalent for ACS_DARROW and but happens to be the ACS char for ACS_BTEE.
I have a thought or tow on solving this, but I would prefer some expert advice as to how best to handle this problem. The output under Linux term is great and would like to have consistency on other terms.
Using ncurse 6 as packaged with Ubuntu 16.04.3 LTS
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Bryan
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