T34: review round 2: bash 3.2 drops its DEBUG trap, which ran for key bindings, missed lone subshells and decided commands under extdebug, so it sends no C, and its D comes from the prompt by the command number; PowerShell takes a program's code only when the line's last pipeline ends in it, as its syntax tree and Get-Command name it; each check waits for the prompt before its line, so a repeated status is the line's own

assets/shell-integration/bash/elyterminal.bash

@@ -13,37 +13,19 @@ else
   [ -r ~/.bashrc ] && builtin source ~/.bashrc
 fi
 _ely_ran=
-_ely_sent=
 _ely_n=0
-_ely_armed=
 _ely_ps0=
 if (( BASH_VERSINFO[0] * 100 + BASH_VERSINFO[1] >= 404 )); then
   # PS0 runs in the shell, so its subscript can note that a command ran.
   _ely_ps0='${_ely_note[_ely_ran=1]-}\e]133;C\a'
-else
-  # bash 3.2 has no PS0: the DEBUG trap sends C, then runs the user's own trap with $? and $_ kept.
-  _ely_debug() {
-    builtin local status=$?
-    if [ -n "$_ely_armed" ] && [[ $BASH_COMMAND != _ely_* ]]; then
-      _ely_armed=
-      _ely_ran=1
-      builtin printf '\e]133;C\a'
-    fi
-    builtin return $status
-  }
-  builtin eval "_ely_trap=($(builtin trap -p DEBUG))"
-  builtin trap "_ely_debug \"\$_\"${_ely_trap[2]:+; ${_ely_trap[2]}}" DEBUG
-  builtin unset _ely_trap
 fi
 _ely_prompt() {
   builtin local ret=$? LC_ALL=C char url= i title
-  _ely_armed=
-  _ely_sent=$_ely_ran
   if [ -n "$_ely_ran" ]; then
     builtin printf '\e]133;D;%s\a' "$ret"
     _ely_ran=
   fi
-  _ely_d=([1]=$'\e]133;D;'"$ret"$'\a')
+  [ -n "$_ely_ps0" ] || _ely_d=([1]=$'\e]133;D;'"$ret"$'\a')
   for (( i = 0; i < ${#PWD}; i++ )); do
     char=${PWD:i:1}
     case $char in
@@ -58,9 +40,9 @@ _ely_prompt() {
 # Last, after anything that sets PS1 or PS0.
 _ely_mark() {
   if [[ $PS1 != *'\e]133;A'* ]]; then
-    if builtin shopt -q promptvars; then
-      # bash 3.2 traps no line that is only a subshell; \# counts it, so the prompt sends its D.
-      PS1='\[${_ely_d[!_ely_sent && _ely_n && \# != _ely_n]-}${_ely_note[_ely_n = \#]-}\e]133;A\a\]'"$PS1"'\[\e]133;B\a\]'
+    if [ -z "$_ely_ps0" ] && builtin shopt -q promptvars; then
+      # bash 3.2 has no PS0; \#, the command number, moves once a command ran.
+      PS1='\[${_ely_d[_ely_n && \# != _ely_n]-}${_ely_note[_ely_n = \#]-}\e]133;A\a\]'"$PS1"'\[\e]133;B\a\]'
     else
       PS1='\[\e]133;A\a\]'"$PS1"'\[\e]133;B\a\]'
     fi
@@ -68,6 +50,5 @@ _ely_mark() {
   if [ -n "$_ely_ps0" ] && builtin shopt -q promptvars && [[ ${PS0-} != *"$_ely_ps0"* ]]; then
     PS0=$_ely_ps0${PS0-}
   fi
-  _ely_armed=1
 }
 PROMPT_COMMAND="_ely_prompt${PROMPT_COMMAND:+;$PROMPT_COMMAND};_ely_mark"