From d4242177daaee9078245570125c5a99e65f55163 Mon Sep 17 00:00:00 2001
From: Eli Zaretskii <eliz@gnu.org>
Date: Sat, 7 Nov 2020 11:19:44 +0200
Subject: [PATCH] Fix 'send-string-to-terminal' writing very long strings

* src/dispnew.c (Fsend_string_to_terminal): Prevent partial writes
by blocking SIGIO while 'fwrite' runs.  (Bug#44320)
---
 src/dispnew.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/dispnew.c b/src/dispnew.c
index 5b6fa51a563..df55b32c718 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -5904,8 +5904,12 @@ when TERMINAL is nil.  */)
 	}
       out = tty->output;
     }
+  /* STRING might be very long, in which case fwrite could be
+     interrupted by SIGIO.  So we temporarily block SIGIO.  */
+  unrequest_sigio ();
   fwrite (SDATA (string), 1, SBYTES (string), out);
   fflush (out);
+  request_sigio ();
   unblock_input ();
   return Qnil;
 }
-- 
2.39.2