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

PRD.md

@@ -44,7 +44,7 @@ Ghostty is the bar for what the terminal does. ELYTerminal owns its engine on `a
 
 - PTY: alacritty's `tty` and event loop. The pty is wrapped so its reader passes bytes through an OSC scanner. The scanner reports the working directory and prompt marks.
 - Shell integration for zsh, bash, fish and PowerShell, injected at launch as Ghostty does: each prompt sends OSC 7 and a title. A shell without integration reports nothing, and the panels say so.
-- Prompt marks, OSC 133: the shell integration marks where each prompt starts (A) and ends (B), where a command starts (C), and where it ends with its exit status (D); the terminal reads any program's OSC 133. Cmd-Up and Cmd-Down, and Cmd-Shift-Up and Cmd-Shift-Down, on macOS, Ctrl-Shift-Up and Ctrl-Shift-Down elsewhere, scroll to the prompt before or after the view's top, as in Ghostty.
+- Prompt marks, OSC 133: the shell integration marks where each prompt starts (A) and ends (B), where a command starts (C), and where it ends with its exit status (D), all but C on macOS's bash 3.2, which has no hook for it; the terminal reads any program's OSC 133. Cmd-Up and Cmd-Down, and Cmd-Shift-Up and Cmd-Shift-Down, on macOS, Ctrl-Shift-Up and Ctrl-Shift-Down elsewhere, scroll to the prompt before or after the view's top, as in Ghostty.
 - Program status, OSC 7501 revision 0.4: each terminal keeps the records programs report (state, id, kind, progress, app, title, msg), checked as the spec checks them; a new prompt drops working, blocked and idle records, a full reset drops them all; the terminal answers the support query with the states and kinds it takes.
 - Progress, OSC 9;4: set, error, indeterminate and pause stand as the root record until a program reports OSC 7501, until a full reset.
 - Notifications: OSC 9 (iTerm2), OSC 777 notify (rxvt) and OSC 99 (kitty: title and body in chunks, base64, ids, occasions, focus and report on activation, close, and its query); ConEmu's other OSC 9 commands are no notifications.