xterm not supporting REP escape sequence - Tera Term Ticket #39451 on OSDN

The xterm definition changed from ncurses-6.0 to ncurses-6.1:

comparing xterm to xterm.
    comparing booleans.
    comparing numbers.
    comparing strings.
        kmous: '\E[M', '\E[<'.
        rep: NULL, '%p1%c\E[%p2%{1}%-%db'.
        rmcup: '\E[?1049l', '\E[?1049l\E[23;0;0t'.
        smcup: '\E[?1049h', '\E[?1049h\E[22;0;0t'.
        u8: '\E[?1;2c', '\E[?%[;0123456789]c'.

Running an ncurses-6.1 application under teraterm causes horizontal window lines to be shortened to a length of one. The new REP sequence (repeat character) in ncurses-6.1 is probably the cause. ncurses-6.0 renders correctly in teraterm.

For reference, Putty added REP support in 0.71 (https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html), and I do recall seeing corrupted output when using older Putty.

Teraterm version is 4.103.