prompt miscalculations seen more often in 3.1.0?

[Dan Jacobson]

Prompt miscalculations seems to happen slightly more in 3.1.0? Live
with this below script for a few days and often using ^R, ^A, combined
with inserting characters etc. and you too should see how often bash
miscalculates where things are on the screen. It's hard to describe,
so no precise examples coming forth from me this time, but that's
good, as living with this for a few days and you will discover even
more problems perhaps. If bash had an emacs-like view-lossage command
(very good idea!) I would be more inclined to give a precise example.
Anyway, I often reach for ^L these days. BASH_VERSION='3.1.0(1)-release'

case z-$TERM in
    z-rxvt)
        my_color_on="\[\e[01;35m\]" my_color_off="\[\e[00m\]"
        if test -w /
        then my_color_on="\[\e[01;41;30m\]"
        fi
esac
#Mr. http://cfaj.freeshell.org:
PROMPT_COMMAND='prompt_tricks_z=" $?"; prompt_tricks_z=${prompt_tricks_z# 0}
 case $PWD in $HOME) pwd=\~;; *) pwd=${PWD##*/};; esac'
PS1=$SPECIAL_PS1"$my_color_on\A\$prompt_tricks_z \$pwd\\$""$my_color_off "