From b84a067e0f004e960dc743813ed3e41987149df4 Mon Sep 17 00:00:00 2001
From: Gabriel Baraldi <baraldigabriel@gmail.com>
Date: Mon, 16 Mar 2026 22:48:50 -0300
Subject: [PATCH] unix,tty: don't drain when setting the TTY mode (#4945)
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This avoids a blocking syscall (essentially a write)–and thus potential
deadlock–in the asynchronous IO path.
---
 src/unix/tty.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/unix/tty.c b/src/unix/tty.c
index b86107202..ae7367933 100644
--- a/src/unix/tty.c
+++ b/src/unix/tty.c
@@ -52,7 +52,7 @@
  */
 static int isreallyatty(int file) {
   int rc;
- 
+
   rc = !ioctl(file, TXISATTY + 0x81, NULL);
   if (!rc && errno != EBADF)
       errno = ENOTTY;
@@ -333,8 +333,8 @@ int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
       UNREACHABLE();
   }
 
-  /* Apply changes after draining */
-  rc = uv__tcsetattr(fd, TCSADRAIN, &tmp);
+  /* Apply changes now, to avoid blocking. */
+  rc = uv__tcsetattr(fd, TCSANOW, &tmp);
   if (rc == 0)
     tty->mode = mode;