Merge the macOS first-class-host work

1 files changed, 35 insertions, 3 deletions

diff --git a/docs/macos.md b/docs/macos.md
index 9190ca67..e104d3a6 100644
--- a/docs/macos.md
+++ b/docs/macos.md
@@ -369,6 +369,14 @@ second spelling of builtins — `AppDelegate` calls `run("New")`, `run("Save")`,
 `run("Help")`, `run("Tutor")` — and the items with no builtin behind them are
 left out rather than stubbed.
 
+The workspace tag row — the topmost tagline, the one carrying `Newcol Joincol
+Find Grep …` — is not drawn on this shell. `-Dworkspace-tag` (default off for
+`-Dplatform=macos`, on everywhere else) hands the row to the menu bar: the
+core stops reserving the row (`Pardes.topBarHeight`), the grid starts at the
+column tags, and the row's commands live in a **Builtins** menu instead. The
+items are the tag's own words, spelled exactly as a tag Exec would type them,
+and nothing in that menu is editable — it is the tag's buttons, not the tag:
+
 | menu | item | chord | what it does |
 |---|---|---|---|
 | pardes | About pardes | — | AppKit's panel |
@@ -378,6 +386,7 @@ left out rather than stubbed.
 | | New | ⌘N | the `New` builtin |
 | | Save | ⌘S | the `Save` builtin |
 | | Close Window | ⌘W | AppKit; the app terminates after the last one |
+| Builtins | Newcol / Joincol / Find / Grep / Changelog / Dump / NextColor / Debug / Kill | — | the workspace tag's own builtins, `run(word)` |
 | Edit | Paste | ⌘V | the view's own paste path, not a second one |
 | View | Zoom In / Zoom Out / Actual Size | ⌘= / ⌘- / ⌘0 | point size, host-side |
 | Window | Minimize / Zoom | ⌘M / — | AppKit |
@@ -455,6 +464,32 @@ Nested launches use the same inherited 9P address and pane serial as other
 native hosts. They do not inspect ancestor processes or executable names.
 See [the control filesystem](fs.md) for paths and transports.
 
+Two more things this host cannot inherit from its launcher, because a `.app`
+has none:
+
+- **The terminal's identity.** `host_io.ChildEnv` writes `TERM`, `COLORTERM`
+  and `TERM_PROGRAM` over whatever the environment carried and the child is
+  `execve`'d with that array — built before the fork, because a `setenv`
+  between fork and exec can deadlock on the heap a pty reader thread was
+  holding. Every pane is emulated by the bundled VT, so the value describes
+  pardes and never the terminal pardes was started from; `-Dplatform=gui` and
+  the tty shell take the same path, where the difference is only that their
+  launcher usually happened to set something. The names come from
+  `config.child_term` / `child_colorterm` / `child_term_program`, and `TERM`
+  is deliberately `xterm-256color` rather than a name with no installed
+  terminfo entry — `clear`, colour and cursor addressing all resolve through
+  that lookup.
+- **Whether a program has the terminal.** `host_io.ttyTaken` is what
+  `Pardes.takesCommandLine` asks before deciding that Escape is the `Last`
+  builtin rather than a keystroke for the child, and what `Exec` asks before
+  believing a pane is at its prompt. Linux descends `/proc/<pid>/task/<pid>/
+  children`; darwin has neither that nor a children list, so it enumerates the
+  tty's foreground process group with `proc_listpids(PROC_PGRP_ONLY)` and
+  compares each member's `proc_pidpath` against the shell's own. A nested
+  interactive shell is therefore still a prompt, and `bash -c 'sleep 30'` is
+  still taken — the wrapper wears the shell's binary, but `sleep` shares its
+  group. The occupancy suite in `src/host_io.zig` runs on both platforms.
+
 ## Fonts and zoom
 
 The face is the shell's business and the size is the window's, so the two are
@@ -1109,9 +1144,6 @@ used for the table and is not folded into the direct-path claim.
   says nothing either. Wiring it up means a unix-socket frontend loop beside
   the AppKit one, which is `src/detached/client.zig`'s job in the tty and SDL
   shells; see `docs/detached.md`.
-- **`tty_taken` on darwin.** The pull is wired (`ttyTaken`, `src/macos.zig:1838`)
-  but `look.ttyTaken` has no libproc implementation and answers `false`, so an
-  `Exec` here always believes the pane is still at the prompt it forked.
 - **IME and marked text.** Only finished characters reach `pardes_key`, so a
   dead key composes nothing and Option is Alt rather than a compose modifier.
   Real composition means implementing `NSTextInputClient` *and* giving the core