A detached session's pty is sized in pixels too, at the last frontend's cell size or a nominal 8x16 before one attached

forkShell sized a new pty in pixels (ptyWinsize), but the detached
server's resize set xpixel and ypixel to 0, and a pane is resized as it
is placed, so a program in a detached session with no frontend (yazi)
saw a pty with no pixels and drew no images. CSI 14/16/18 t were
already answered at the nominal 8x16 cell.

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

1 files changed, 3 insertions, 1 deletions

diff --git a/src/detached/server.zig b/src/detached/server.zig
index 588912bb..79d1189a 100644
--- a/src/detached/server.zig
+++ b/src/detached/server.zig
@@ -549,7 +549,9 @@ pub const Session = struct {
         if (pane >= s.ptys.len) return;
         const fd = s.ptys[pane].fd;
         if (fd < 0) return;
-        const ws: posix.winsize = .{ .row = rows, .col = cols, .xpixel = 0, .ypixel = 0 };
+        // In pixels too, at the last frontend's cell size (8x16 before
+        // one attached): a program sizes its kitty graphics by them.
+        const ws = host_io.ptyWinsize(s.core, cols, rows);
         _ = posix.system.ioctl(fd, TIOCSWINSZ, @intFromPtr(&ws));
     }