Emacs21 and faces in the hurd console.

[Gianluca Guida <glguida@gmail.com>]

Hi.

Emacs 21 in tty mode maps slanted faces to dimmed text, indipendently
from the terminal support for italic mode.

This patch maps -- if the terminal supports it -- slanted face to
italic fonts. With this patch, then, a properly configured Hurd
console can show italic fonts when in font-lock mode.

I actually tried to made the same work for bold faces, but being the
capability for real bold mode a GNU extension and not being an expert
of terminfo, I don't know the capability code for it. Anybody can
help?

Gianluca

-- 
It was a type of people I did not know, I found them very strange and
they did not inspire confidence at all. Later I learned that I had been
introduced to electronic engineers.
                                                           E. W. Dijkstra

--- src/dispextern.h	2002-11-14 14:15:46.000000000 +0100
+++ /home/glguida/emacs21src-hack/dispextern.h	2005-04-30 16:09:53.000000000 +0200
@@ -1329,6 +1329,7 @@
   unsigned tty_alt_charset_p : 1;
   unsigned tty_reverse_p : 1;
   unsigned tty_blinking_p : 1;
+  unsigned tty_italic_p : 1;
 
   /* 1 means that colors of this face may not be freed because they
      have been copied bitwise from a base face (see
--- src/term.c	2005-04-30 19:32:39.000000000 +0200
+++ /home/glguida/emacs21src-hack/term.c	2005-04-30 17:18:55.000000000 +0200
@@ -96,6 +96,7 @@
 int char_ins_del_ok;		/* Terminal can insert and delete chars */
 int scroll_region_ok;		/* Terminal supports setting the
 				   scroll window */
+int italic_mode_ok;		/* Terminal supports italic mode */
 int scroll_region_cost;		/* Cost of setting a scroll window,
 				   measured in characters */
 int memory_below_frame;		/* Terminal remembers lines
@@ -310,6 +311,10 @@
 
 char *TS_enter_bold_mode;
 
+/* "ZH" -- turn on italics mode.  */
+
+char *TS_start_italic_mode;
+
 /* "mh" -- turn on half-bright mode.  */
 
 char *TS_enter_dim_mode;
@@ -2080,8 +2085,14 @@
 	OUTPUT1_IF (TS_enter_bold_mode);
     }
   else if (face->tty_dim_p)
-    if (MAY_USE_WITH_COLORS_P (NC_DIM))
-      OUTPUT1_IF (TS_enter_dim_mode);
+    {
+      if (MAY_USE_WITH_COLORS_P (NC_DIM))
+	OUTPUT1_IF (TS_enter_dim_mode);
+    }
+  else if (face->tty_italic_p)
+    if (TS_start_italic_mode)
+      OUTPUT1_IF (TS_start_italic_mode);
+  
 
   /* Alternate charset and blinking not yet used.  */
   if (face->tty_alt_charset_p
@@ -2137,6 +2148,7 @@
 	 may not turn off alt-char-mode.  */
       if (face->tty_bold_p
 	  || face->tty_dim_p
+	  || face->tty_italic_p
 	  || face->tty_reverse_p
 	  || face->tty_alt_charset_p
 	  || face->tty_blinking_p
@@ -2345,6 +2357,7 @@
   TS_enter_alt_charset_mode = tgetstr ("as", address);
   TS_exit_alt_charset_mode = tgetstr ("ae", address);
   TS_exit_attribute_mode = tgetstr ("me", address);
+  TS_start_italic_mode = tgetstr ("ZH", address);
   
   MultiUp = tgetstr ("UP", address);
   MultiDown = tgetstr ("DO", address);
@@ -2584,6 +2597,8 @@
 
   fast_clear_end_of_line = TS_clr_line != 0;
 
+  italic_mode_ok = TS_start_italic_mode != 0;
+
   init_baud_rate ();
   if (read_socket_hook)		/* Baudrate is somewhat */
 				/* meaningless in this case */
--- src/xfaces.c	2005-04-30 19:32:23.000000000 +0200
+++ /home/glguida/emacs21src-hack/xfaces.c	2005-04-30 16:10:17.000000000 +0200
@@ -6577,6 +6577,8 @@
     face->background = pixel;
 }
 
+/* Terminal supports italic mode, defined in term.c */
+extern int italic_mode_ok;
 
 /* Realize the fully-specified face with attributes ATTRS in face
    cache CACHE for character C.  Do it for TTY frame CACHE->f.  Value is a
@@ -6602,14 +6604,21 @@
 
   /* Map face attributes to TTY appearances.  We map slant to
      dimmed text because we want italic text to appear differently
-     and because dimmed text is probably used infrequently.  */
+     and because dimmed text is probably used infrequently. 
+     However, if TTY supports "ZH" (start italic mode) we map slant 
+     to it.  */
   weight = face_numeric_weight (attrs[LFACE_WEIGHT_INDEX]);
   slant = face_numeric_slant (attrs[LFACE_SLANT_INDEX]);
 
   if (weight > XLFD_WEIGHT_MEDIUM)
     face->tty_bold_p = 1;
   if (weight < XLFD_WEIGHT_MEDIUM || slant != XLFD_SLANT_ROMAN)
-    face->tty_dim_p = 1;
+    {
+      if (italic_mode_ok)
+	face->tty_italic_p = 1;
+      else
+	face->tty_dim_p = 1;
+    };
   if (!NILP (attrs[LFACE_UNDERLINE_INDEX]))
     face->tty_underline_p = 1;
   if (!NILP (attrs[LFACE_INVERSE_INDEX]))