A terminal pane that closes takes its shell and pty with it, in every front end

The detached server closed a pane's pty only when the shell was respawned,
hit EOF or the session shut down, so rmdir, Del or Delcol on a terminal
left its shell running with nobody to read it; the tty front end and
macOS did the same. Retiring a terminal pane now emits a close_pty
effect, which each host that runs shells answers by hanging the pty up
and ending the shell (the detached server's and the GUI's existing
retire-and-reap path, and a close plus SIGHUP in the tty and macOS
shells).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/gui/gui.zig b/src/gui/gui.zig
index 415b21e8..1d5d3c05 100644
--- a/src/gui/gui.zig
+++ b/src/gui/gui.zig
@@ -3756,6 +3756,10 @@ const Shell = struct {
         };
     }
 
+    fn closePaneShell(ctx: ?*anyopaque, pane: u8) void {
+        shellOf(ctx).closePty(pane);
+    }
+
     fn closePty(s: *Shell, pane: u8) void {
         const pt = if (s.ptys[pane]) |*pt| pt else return;
         if (pt.fd < 0) return;
@@ -3831,6 +3835,7 @@ const Shell = struct {
         .pty_write = ptyWrite,
         .pty_resize = ptyResize,
         .pty_signal = ptySignal,
+        .close_pty = closePaneShell,
         .tty_taken = ttyTaken,
         .write_file = writeFile,
         .write_dump = writeDump,