From 4fdb81fa30b7648ed832b43021ece1e55010d694 Mon Sep 17 00:00:00 2001
From: Red Bear OS <build@redbearos.org>
Date: Sat, 18 Jul 2026 17:29:33 +0900
Subject: [PATCH] DIAG(ptyd): log pty.input line-discipline (icanon/vmin ->
 cooked/mosi) + slave read mosi state

---
 ptyd/src/pty.rs     | 13 +++++++++++++
 ptyd/src/subterm.rs |  8 ++++++++
 2 files changed, 21 insertions(+)

diff --git a/ptyd/src/pty.rs b/ptyd/src/pty.rs
index 80cd2957a4..f68eb72f91 100644
--- a/ptyd/src/pty.rs
+++ b/ptyd/src/pty.rs
@@ -246,6 +246,19 @@ impl Pty {
         }
 
         self.update();
+        if !buf.is_empty() {
+            let cc = self.termios.c_cc;
+            eprintln!(
+                "ptyd-diag: input {} bytes icanon={} echo={} vmin={} vtime={} -> cooked={} mosi={}",
+                buf.len(),
+                icanon,
+                echo,
+                cc[VMIN],
+                cc[VTIME],
+                self.cooked.len(),
+                self.mosi.len(),
+            );
+        }
     }
 
     pub fn output(&mut self, buf: &[u8]) {
diff --git a/ptyd/src/subterm.rs b/ptyd/src/subterm.rs
index beda848fa3..f17e4a8565 100644
--- a/ptyd/src/subterm.rs
+++ b/ptyd/src/subterm.rs
@@ -51,6 +51,14 @@ impl Resource for PtySubTerm {
 
             pty.update();
 
+            if !pty.mosi.is_empty() {
+                eprintln!(
+                    "ptyd-diag: subterm read: mosi has {} packet(s), first len {}",
+                    pty.mosi.len(),
+                    pty.mosi.front().map(|p| p.len()).unwrap_or(0),
+                );
+            }
+
             if let Some(packet) = pty.mosi.pop_front() {
                 let mut i = 0;