Kill signals a command only while it runs, and only the pane it was meant for

A signal effect carried only a slot, so a Kill followed in the same step by
the pane's closing and its slot's reuse signalled the new pane's child; and a
command pane whose child had exited and been reaped kept a process group id
another process could take. The effect now carries the pane's serial, checked
as it is performed, and a host signals no command whose exit it has recorded;
the core already sends Kill only to a command it has not been told is done.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/src/builtins.zig b/src/builtins.zig
index 4815a114..5273cf37 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -440,7 +440,7 @@ pub const Kill = struct {
                         if (std.mem.eql(u8, w, first)) break;
                     } else continue;
                 }
-                c.p.emit(.{ .signal_pty = .{ .pane = @intCast(id), .sig = .term } });
+                c.p.emit(.{ .signal_pty = .{ .pane = @intCast(id), .serial = pane.serial, .sig = .term } });
                 stopped = true;
                 continue;
             };