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"

assets/shell-integration/pwsh/elyterminal.ps1

@@ -11,7 +11,7 @@ function global:prompt {
             # Each native run sets a new $LASTEXITCODE, equal or not; strict mode refuses an unset one.
             $exit = Get-Variable LASTEXITCODE -Scope Global -ValueOnly -ErrorAction Ignore
             $ran = $null -ne $exit -and -not [object]::ReferenceEquals($exit, $global:ElyExit)
-            $code = if ($ran -and $exit -ne 0) { $exit } else { 1 }
+            $code = if ($global:ElyNative -and $ran -and $exit -ne 0) { $exit } else { 1 }
         }
         [Console]::Write("$esc]133;D;$code$bel")
         $global:ElyRan = $false
@@ -38,6 +38,20 @@ if (Test-Path Function:\PSConsoleHostReadLine) {
         if (-not [string]::IsNullOrWhiteSpace($line)) {
             $global:ElyRan = $true
             $global:ElyExit = Get-Variable LASTEXITCODE -Scope Global -ValueOnly -ErrorAction Ignore
+            # A program's exit code is the line's when the line's last pipeline ends in it.
+            $global:ElyNative = $false
+            $ast = [System.Management.Automation.Language.Parser]::ParseInput($line, [ref]$null, [ref]$null)
+            # Strict mode refuses .Count on one statement alone, so the statements stay a list.
+            $statements = @(if ($ast.EndBlock) { $ast.EndBlock.Statements })
+            $last = if ($statements.Count) { $statements[$statements.Count - 1] }
+            if ($last -is [System.Management.Automation.Language.PipelineAst]) {
+                $elements = $last.PipelineElements
+                $end = $elements[$elements.Count - 1]
+                $name = if ($end -is [System.Management.Automation.Language.CommandAst]) { $end.GetCommandName() }
+                $info = if ($name) { Get-Command -Name $name -ErrorAction Ignore | Select-Object -First 1 }
+                while ($info -and $info.CommandType -eq 'Alias') { $info = $info.ResolvedCommand }
+                $global:ElyNative = $null -ne $info -and $info.CommandType -in 'Application', 'ExternalScript'
+            }
             [Console]::Write("$([char]27)]133;C$([char]7)")
         }
         $line