From 5f6030b13cb24ad209b96f27f0f95152ceab439d Mon Sep 17 00:00:00 2001
From: Daniel Bertalan <dani@danielbertalan.dev>
Date: Mon, 25 Oct 2021 14:36:05 +0200
Subject: [PATCH] Kernel+LibC: Default to 8-bit characters in TTY

Some ports (like `bc` with history enabled) sensibly set the termios
character size to 8 bits.

Previously, we left the character size value (given by the bitmask
CSIZE) as zero by default (meaning 5 bits per character), and returned
ENOTIMPL whenever someone modified it. This was dumb.
---
 Kernel/TTY/TTY.cpp                        | 10 +++++-----
 Userland/Libraries/LibC/sys/ttydefaults.h |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Kernel/TTY/TTY.cpp b/Kernel/TTY/TTY.cpp
index 86ea95cd94..0d3e6aec38 100644
--- a/Kernel/TTY/TTY.cpp
+++ b/Kernel/TTY/TTY.cpp
@@ -438,12 +438,12 @@ KResult TTY::set_termios(const termios& t)
         }
     }
 
+    if ((m_termios.c_cflag & CSIZE) != CS8) {
+        dbgln("FIXME: Character sizes other than 8 bits are not supported");
+        rc = ENOTIMPL;
+    }
+
     static constexpr FlagDescription unimplemented_cflags[] = {
-        { CSIZE, "CSIZE" },
-        { CS5, "CS5" },
-        { CS6, "CS6" },
-        { CS7, "CS7" },
-        { CS8, "CS8" },
         { CSTOPB, "CSTOPB" },
         { CREAD, "CREAD" },
         { PARENB, "PARENB" },
diff --git a/Userland/Libraries/LibC/sys/ttydefaults.h b/Userland/Libraries/LibC/sys/ttydefaults.h
index de8eeee645..2db57a43b2 100644
--- a/Userland/Libraries/LibC/sys/ttydefaults.h
+++ b/Userland/Libraries/LibC/sys/ttydefaults.h
@@ -11,7 +11,7 @@
 #define TTYDEF_LFLAG_NOECHO (ISIG | ICANON)
 #define TTYDEF_LFLAG_ECHO (TTYDEF_LFLAG_NOECHO | ECHO | ECHOE | ECHOK | ECHONL)
 #define TTYDEF_LFLAG TTYDEF_LFLAG_ECHO
-#define TTYDEF_CFLAG (0)
+#define TTYDEF_CFLAG (CS8)
 #define TTYDEF_SPEED (B9600)
 
 #define CTRL(c) (c & 0x1F)