T35: review round 2: a program's link inside a prompt keeps its target and carries the prompt's number in its id, and a prompt that starts inside a link left open opens it again with the number, so a prompt all in links still starts on its first row; controls vte runs inside an escape go on before it, so only the ESC waits and a long run of them keeps the pty reading

AGENTS.md

@@ -97,4 +97,4 @@ ELYTerminal. A terminal on GPUI and Ely components. `PRD.md` says what it does;
 - 2026-10-16: the main window opens at the size it was left at, which the owner asked for on macOS, Windows and Linux: `window_width` and `window_height` in the settings hold the size gpui's `window_bounds` gives 0.5 s after the bounds settle, saved through `SettingsStore::update`, which writes only a change, so a drag saves once and a move saves nothing. A maximized, full-screen or hidden window keeps the size from before; its state and size are read once they settle, since X11 marks a window maximized after its new size, gpui's X11 window then gives a maximized window's own size, and it calls a maximized window unmaximized while minimized. A window that shows again, uncovered, restored or back on its screen, is read again, so a size it took just before it hid is kept; a size it takes in the half second before it closes, or before it hides until the app quits, is lost. The window is no smaller than 100 by 100, the least the settings keep, or a smaller size the platform allows could not be kept. The window opens centered at whole points, since macOS grows a window by a point on a side whose edge falls on a half point; its place is not kept, and a kept side past the primary display's visible area shrinks to it, logged. A size outside 100 to 16384 stops the start, as any value out of range does.
 - 2026-10-16: the sessions and right columns resize by a drag on their border toward the terminal, which the owner asked for on macOS, Windows and Linux. Ely's `ShellColumn::resizable`, added to Ely for this, puts Ely's `resize_handle` on the border toward the filling column, the sessions column's right and the right column's left: the handle draws that border, a filled hairline, since gpui paints a border no wider than half its box, and the line it drew at first showed half a pixel on macOS and none on X11; it occludes the header under it, so a press there drags the border, not the window, on Windows too, where an unoccluded drag region takes the press as the caption. A drag sets off from the wider of the width drawn and the one kept: a header's parts may hold a column wider, and a window too narrow for both widths squeezes them, where a drag from the squeezed width jumped back against the pointer; a drag that has not moved sideways changes nothing, and one that comes back where it set off gives the width it had. A set width in Ely became a flex basis, so a column holds its header's own parts: at a set width under them, Windows' caption buttons ran out of the window. The widths, 160 to 960 pixels, show at once and are saved in `sessions_width` and `panel_width` through `SettingsStore::update` 0.5 s after a drag rests, as the window's size is; a drag in the half second before the window closes is lost, and a save the store refuses puts the columns back. A window too narrow for both yields the terminal its header's width, as Ely's set widths give way.
 - 2026-10-16: prompts and commands carry OSC 133 marks, which the owner asked for, read as Ghostty reads them: A or N starts a prompt, B or I ends it, C starts a command's output, and D ends the command with its status, D's first option, none when that is no number. The tap reads any program's marks before the parser, so it never sees the cursor: A's fresh line and L, which need it, are not done, and P adds nothing to A. Each session keeps the status its last command ended with. The integration marks what the shell leaves unmarked, and the user's prompt still sees the command's status. zsh: precmd reads `$?` and sends D after a command ran, preexec sends C, and a last precmd hook wraps PS1 in A and B under `prompt_percent`, which the first prompt says while it is off; it moves to the end of `precmd_functions` at each prompt, since a theme that sets PS1 in a hook of its own loads after it, and at the first prompt `sched +0` wraps it once more, since zsh runs due events after every precmd hook; that call returns the command's status, which the prompt shows, but it would reset `$pipestatus`, so it serves the first prompt alone. bash: PROMPT_COMMAND's first entry reads `$?`, which each entry resets, and its last wraps PS1. From bash 4.4 PS0 sends C and its subscript notes that a command ran, since bash prints no PS0 for an empty line, and the first entry sends D for it; both need `promptvars`, on by default. macOS's bash 3.2 has no PS0 and nothing else between reading a line and running it: its DEBUG trap runs for a key binding's command (`bind -x`) as for a typed one, with nothing to tell the two apart, runs for no line that is only a subshell, and under `extdebug` its status decides whether a command runs. So bash 3.2 sends no C, and Ghostty's automatic integration skips bash 3.2. Its D comes from PS1 once `\#`, the command number, has moved, which neither a key binding nor an empty line does; readline sends a prompt's escapes again at each redraw, so that D goes again with it, the same status. Every mark of a command rides an expansion, which `promptvars` turns on, so while it is off at start the script says so rather than mark nothing without a word. fish 4.3 marks its own prompts and commands, fish 4.0 all but B, older ones none: the script adds what the running fish lacks, around the prompt shown, and wraps it again when the user's changes. PowerShell: the prompt reads `$?` first and sets it back for the user's prompt through `Write-Error '' -ErrorAction Ignore`, which adds nothing to `$Error`. A failure ends with `$LASTEXITCODE` when a program set it during the line, since each run stores a new object, equal or not, which `[object]::ReferenceEquals` tells apart, unless the line surely ends in PowerShell: its syntax tree, read as PSReadLine hands the line over, ends in a cmdlet, as `Get-Command` resolves the name, aliases through, in a name not found, or in no command; such a line ends with 1, a cmdlet's failure under `-ErrorAction Ignore` too. A line that ends in a block, a function, a script or a call through a variable takes the code of a program it ran: only a hook on every command lookup would name the last command run, and it slowed a loop of commands by half. `$LASTEXITCODE` is read through `Get-Variable`, since strict mode refuses an unset variable and a prompt that fails falls back to `PS>`. C goes out when PSReadLine hands over a line that is not blank; without PSReadLine the script says it marks no command. herdr passes no OSC 133 on, so a session running herdr keeps the status from before it.
-- 2026-10-16: the view jumps between prompts, which the owner asked for, as Ghostty jumps: Cmd-Up and Cmd-Down, with Shift or without, on macOS, Ctrl-Shift-Up and Ctrl-Shift-Down elsewhere, scroll to the prompt that starts before or after the view's top; a prompt on the screen's last page means the bottom, which the view cannot pass, and with none there nothing moves. alacritty's rows hold no marks, and the tap, which reads before the parser, never sees the cursor, so the tap rewrites what goes to the parser: an OSC that may be a mark is held whole until it ends and read as `marks` reads it, and a prompt's start becomes an OSC 8 link of the terminal's own, its target `\x7f`, which no program names, its id the prompt's number; the prompt's end closes it. The parser stamps each cell the prompt prints with the link, SGR 0 keeps it, and it rides the cells through scroll, reflow and history; a prompt starts on the first row that shows its number, blank rows within it passed. A program's own link keeps its cells: a prompt that starts inside one leaves it open, and its end inside a prompt opens the prompt's link again; a cursor restore that brings back a link passes the rewrite by. An OSC held, a body of 4096 bytes at most as the scanner keeps it and twice that with the controls vte skips, shows nothing until it ends; controls vte runs inside an escape go on first. A rewrite adds at most 14 bytes to a sequence of 6 or more, so the tap reads a quarter of the buffer's room. Links, Cmd-press among them, pass over the prompt's link. The tap's OSC scanner ends a body as vte does, at BEL, ESC, CAN or SUB, and skips the controls vte skips, so a mark and its link agree.
+- 2026-10-16: the view jumps between prompts, which the owner asked for, as Ghostty jumps: Cmd-Up and Cmd-Down, with Shift or without, on macOS, Ctrl-Shift-Up and Ctrl-Shift-Down elsewhere, scroll to the prompt that starts before or after the view's top; a prompt on the screen's last page means the bottom, which the view cannot pass, and with none there nothing moves. alacritty's rows hold no marks, and the tap, which reads before the parser, never sees the cursor, so the tap rewrites what goes to the parser: an OSC that may be a mark is held whole until it ends and read as `marks` reads it, and a prompt's start becomes an OSC 8 link of the terminal's own, its target `\x7f`, which no program names, its id `\x7f` and the prompt's number; the prompt's end closes it. The parser stamps each cell the prompt prints with the link, SGR 0 keeps it, and it rides the cells through scroll, reflow and history; a prompt starts on the first row that shows its number, blank rows within it passed. A program's own link keeps its target and takes the prompt's number in its id: one opened inside a prompt carries it, and a prompt that starts inside one opens it again with the number, a target of 256 bytes at most, and gives back its own id at the prompt's end; its end inside a prompt takes the prompt's link up again. A cursor restore that brings back a link passes the rewrite by. An OSC held, a body of 4096 bytes at most as the scanner keeps it and twice that with the controls vte skips, shows nothing until it ends; controls vte runs inside an escape go on before it, so only the ESC waits. A rewrite makes a sequence 36 times its size at most, a mark of 8 bytes a link of 276, so the tap reads a 36th of the buffer's room. Links, Cmd-press among them, pass over the prompt's link. The tap's OSC scanner ends a body as vte does, at BEL, ESC, CAN or SUB, and skips the controls vte skips, so a mark and its link agree.