Add support for italic text on ttys.

* src/dispextern.h: Replace unused TTY_CAP_BLINK with TTY_CAP_ITALIC.
(struct face): Remove unused fields tty_dim_p, tty_blinking_p, and
tty_alt_charset_p.  Add tty_italic_p.

* src/term.c: Support italics in capable terminals.
(no_color_bit): Replace unused NC_BLINK with NC_ITALIC.
(turn_on_face): Output using TS_enter_italic_mode if available.
Don't handle unused blinking and alt-charset cases.
(turn_off_face): Handle italic case; discard unused tty_blinking_p
and tty_alt_charset_p cases.
(tty_capable_p, init_tty): Support italics.

* src/termchar.h (struct tty_display_info): Add field for italics.
Remove unused blink field.

* src/xfaces.c (tty_supports_face_attributes_p, realize_tty_face):
Handle slant.

Fixes: debbugs:9652

1 files changed, 4 insertions, 8 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index 979ade70bfc..b877bf9965a 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1609,15 +1609,12 @@ struct face
   unsigned strike_through_color_defaulted_p : 1;
   unsigned box_color_defaulted_p : 1;
 
-  /* TTY appearances.  Blinking is not yet implemented.  Colors are
-     found in `lface' with empty color string meaning the default
-     color of the TTY.  */
+  /* TTY appearances.  Colors are found in `lface' with empty color
+     string meaning the default color of the TTY.  */
   unsigned tty_bold_p : 1;
-  unsigned tty_dim_p : 1;
+  unsigned tty_italic_p : 1;
   unsigned tty_underline_p : 1;
-  unsigned tty_alt_charset_p : 1;
   unsigned tty_reverse_p : 1;
-  unsigned tty_blinking_p : 1;
 
   /* 1 means that colors of this face may not be freed because they
      have been copied bitwise from a base face (see
@@ -2979,8 +2976,7 @@ enum tool_bar_item_image
 #define TTY_CAP_UNDERLINE       0x02
 #define TTY_CAP_BOLD            0x04
 #define TTY_CAP_DIM             0x08
-#define TTY_CAP_BLINK           0x10
-#define TTY_CAP_ALT_CHARSET     0x20
+#define TTY_CAP_ITALIC          0x10
 
 
 /***********************************************************************