Changes for separate unspecified foreground and background colors

on character terminals:

* dispextern.h (FACE_TTY_DEFAULT_FG_COLOR)
(FACE_TTY_DEFAULT_BG_COLOR):  New macros.

* xfaces.c (Qunspecified_fg, Qunspecified_bg): New variables.
(syms_of_xfaces): Initialize and staticpro them.
(tty_defined_color): If the color name is unspecified-fg or
unspecified-bg, return FACE_TTY_DEFAULT_FG_COLOR and
FACE_TTY_DEFAULT_BG_COLOR, respectively, as the pixel value.
(tty_color_name): If the color pixel value is either
FACE_TTY_DEFAULT_FG_COLOR or FACE_TTY_DEFAULT_BG_COLOR, return
Qunspecified_fg or Qunspecified_bg, respectively.
(Finternal_set_lisp_face_attribute): Allow values Qunspecified_fg
and Qunspecified_bg for foreground and background colors.
(realize_default_face): If the foreground and background colors
are not specified, default to Qunspecified_fg and Qunspecified_bg.
(realize_tty_face): By default, set the face colors to
FACE_TTY_DEFAULT_FG_COLOR and FACE_TTY_DEFAULT_BG_COLOR.
[MSDOS]: Handle FACE_TTY_DEFAULT_FG_COLOR and
FACE_TTY_DEFAULT_BG_COLOR when face colors are not defined.
Reverse the colors if the default colors were reversed.

* dispnew.c (init_display): Initialize the frame pixels of the
initial frame to FACE_TTY_DEFAULT_FG_COLOR and
FACE_TTY_DEFAULT_BG_COLOR.

* term.c (turn_on_face): If the default fore- and background
colors are reversed, enter inverse video mode.  Don't send color
escape sequences for unspecified foreground and background colors.
(turn_off_face): Handle unspecified-fg and unspecified-bg colors.

* dosfns.c (unspecified_colors): New variable.
(msdos_stdcolor_idx): Handle unspecified-fg and unspecified-bg
color names, return FACE_TTY_DEFAULT_FG_COLOR and
FACE_TTY_DEFAULT_BG_COLOR, respectively.
(msdos_stdcolor_name): Handle FACE_TTY_DEFAULT_FG_COLOR and
FACE_TTY_DEFAULT_BG_COLOR, return Qunspecified_fg and
Qunspecified_bg, respectively.

* msdos.c (IT_set_face): Support FACE_TTY_DEFAULT_FG_COLOR and
FACE_TTY_DEFAULT_BG_COLOR as pixel values.

* faces.el (face-read-integer, read-face-attribute)
(color-defined-p, color-values): Allow color values unspecified-fg
and unspecified-bg, handle them as unspecified.

1 files changed, 15 insertions, 3 deletions

diff --git a/src/dosfns.c b/src/dosfns.c
index 857d16bd9b2..feb9080b7c7 100644
--- a/src/dosfns.c
+++ b/src/dosfns.c
@@ -409,6 +409,10 @@ static char *vga_colors[16] = {
   "lightred", "lightmagenta", "yellow", "white"
 };
 
+static char *unspecified_colors[] = {
+  "unspecified-fg", "unspecified-bg", "unspecified"
+};
+
 /* Given a color name, return its index, or -1 if not found.  Note
    that this only performs case-insensitive comparison against the
    standard names.  For anything more sophisticated, like matching
@@ -424,17 +428,25 @@ msdos_stdcolor_idx (const char *name)
     if (strcasecmp (name, vga_colors[i]) == 0)
       return i;
 
-  return FACE_TTY_DEFAULT_COLOR;
+  return
+    strcmp (name, unspecified_colors[0]) == 0 ? FACE_TTY_DEFAULT_FG_COLOR
+    : strcmp (name, unspecified_colors[1]) == 0 ? FACE_TTY_DEFAULT_BG_COLOR
+    : FACE_TTY_DEFAULT_COLOR;
 }
 
 /* Given a color index, return its standard name.  */
 Lisp_Object
 msdos_stdcolor_name (int idx)
 {
-  extern Lisp_Object Qunspecified;
+  extern Lisp_Object Qunspecified, Qunspecified_fg, Qunspecified_bg;
 
   if (idx < 0 || idx >= sizeof (vga_colors) / sizeof (vga_colors[0]))
-    return Qunspecified;        /* meaning the default */
+    {
+      return
+        idx == FACE_TTY_DEFAULT_FG_COLOR ? Qunspecified_fg
+        : idx == FACE_TTY_DEFAULT_BG_COLOR ? Qunspecified_bg
+        : Qunspecified; /* meaning the default */
+    }
   return build_string (vga_colors[idx]);
 }