Setting it to N, beside dropping runes, also disables old-style support
for all-caps OLCUC. To get those 40 years old terminals to work, set
CONFIG_TTY_RUNES=y which will DTRT when stty iutf8 is off.
Signed-off-by: Adam Borowski <kilob...@angband.pl>
---
drivers/tty/Kconfig | 17 +++++++++++++++++
drivers/tty/n_tty.c | 10 ++++++++++
2 files changed, 27 insertions(+)
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index 95103054c0e4..cfeed2b196e5 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -151,6 +151,23 @@ config LEGACY_PTY_COUNT
When not in use, each legacy PTY occupies 12 bytes on 32-bit
architectures and 24 bytes on 64-bit architectures.
+config TTY_RUNES
+ bool "Runes on OLCUC"
+ default y
+ ---help---
+ Certain terminals from the days of Unix' infancy supported only
+ all-caps, so-called "Great Runes". Linux still has rudimentary
+ support for those, although how can you connect one is another
+ matter; you enable that via "stty olcuc".
+
+ On anything modern, though (as in "stty iutf8"), you do get actual
+ runes. You need userspace fonts for that; modern distributions
+ tend to install both raster (xterm/rxvt) and TrueType (most
+ terminals) fonts on their default GUI setups. Alas, this is not
+ the case on console due to sharply limited character sets.
+
+ C'mon, you know you want to say Y!
+
config BFIN_JTAG_COMM
tristate "Blackfin JTAG Communication"
depends on BLACKFIN
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 3b8b745eb7cf..14d090576f09 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -123,7 +123,9 @@ struct n_tty_data {
unsigned int column;
unsigned int canon_column;
size_t echo_tail;
+#ifdef CONFIG_TTY_RUNES
unsigned int vt_state;
+#endif
struct mutex atomic_read_lock;
struct mutex output_lock;
@@ -395,6 +397,7 @@ static inline int is_continuation(unsigned char c, struct
tty_struct *tty)
return I_IUTF8(tty) && is_utf8_continuation(c);
}
+#ifdef CONFIG_TTY_RUNES
/* process one OLCUC char (possibly partial unicode)
*
* We need to partially parse ANSI sequences to avoid uppercasing them;
@@ -475,6 +478,7 @@ static int do_olcuc_char(unsigned char c, struct tty_struct
*tty, int space)
tty_put_char(tty, c);
return 1;
}
+#endif
/**
* do_output_char - output one character
@@ -546,8 +550,10 @@ static int do_output_char(unsigned char c, struct
tty_struct *tty, int space)
ldata->column--;
break;
default:
+#ifdef CONFIG_TTY_RUNES
if (O_OLCUC(tty))
return do_olcuc_char(c, tty, space);
+#endif
if (!iscntrl(c) && !is_continuation(c, tty))
ldata->column++;
break;
@@ -650,8 +656,10 @@ static ssize_t process_output_block(struct tty_struct *tty,
ldata->column--;
break;
default:
+#ifdef CONFIG_TTY_RUNES
if (O_OLCUC(tty))
goto break_out;
+#endif
if (!iscntrl(c) && !is_continuation(c, tty))
ldata->column++;
break;
@@ -1975,7 +1983,9 @@ static int n_tty_open(struct tty_struct *tty)
ldata->num_overrun = 0;
ldata->no_room = 0;
ldata->lnext = 0;
+#ifdef CONFIG_TTY_RUNES
ldata->vt_state = ESnormal;
+#endif
tty->closing = 0;
/* indicate buffer work may resume */
clear_bit(TTY_LDISC_HALTED, &tty->flags);
--
2.11.0
