Have nobreak-char-display handle U+2010 and U+2011.

See discussion at
http://lists.gnu.org/archive/html/emacs-devel/2011-10/msg00747.html

* src/xdisp.c (get_next_display_element): Handle U+2010 and U+2011
with nobreak-char-display too.

2 files changed, 43 insertions, 32 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d21e6383764..ce049ebfc84 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2011-10-18  Chong Yidong  <cyd@gnu.org>
+
+        * xdisp.c (get_next_display_element): Handle U+2010 and U+2011
+        with nobreak-char-display too.
+
 2011-10-18  Eli Zaretskii  <eliz@gnu.org>
 
         Fix part 3 of bug#9771.
diff --git a/src/xdisp.c b/src/xdisp.c
index 43907ccc03a..75763616f72 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -6371,8 +6371,8 @@ get_next_display_element (struct it *it)
         {
           Lisp_Object dv;
           struct charset *unibyte = CHARSET_FROM_ID (charset_unibyte);
-          enum { char_is_other = 0, char_is_nbsp, char_is_soft_hyphen }
-          nbsp_or_shy = char_is_other;
+          int nonascii_space_p = 0;
+          int nonascii_hyphen_p = 0;
           int c = it->c;        /* This is the character to display.  */
 
           if (! it->multibyte_p && ! ASCII_CHAR_P (c))
@@ -6424,10 +6424,15 @@ get_next_display_element (struct it *it)
               goto get_next;
             }
 
+          /* If `nobreak-char-display' is non-nil, we display
+             non-ASCII spaces and hyphens specially.  */
           if (! ASCII_CHAR_P (c) && ! NILP (Vnobreak_char_display))
-            nbsp_or_shy = (c == 0xA0   ? char_is_nbsp
-                           : c == 0xAD ? char_is_soft_hyphen
-                           :             char_is_other);
+            {
+              if (c == 0xA0)
+                nonascii_space_p = 1;
+              else if (c == 0xAD || c == 0x2010 || c == 0x2011)
+                nonascii_hyphen_p = 1;
+            }
 
           /* Translate control characters into `\003' or `^C' form.
              Control characters coming from a display table entry are
@@ -6435,7 +6440,8 @@ get_next_display_element (struct it *it)
              the translation.  This could easily be changed but I
              don't believe that it is worth doing.
 
-             NBSP and SOFT-HYPEN are property translated too.
+             The characters handled by `nobreak-char-display' must be
+             translated too.
 
              Non-printable characters and raw-byte characters are also
              translated to octal form.  */
@@ -6446,14 +6452,15 @@ get_next_display_element (struct it *it)
                       && it->glyph_row
                       && (it->glyph_row->mode_line_p || it->avoid_cursor_p))
                   || (c != '\n' && c != '\t'))
-               : (nbsp_or_shy
+               : (nonascii_space_p
+                  || nonascii_hyphen_p
                   || CHAR_BYTE8_P (c)
                   || ! CHAR_PRINTABLE_P (c))))
             {
-              /* C is a control character, NBSP, SOFT-HYPEN, raw-byte,
-                 or a non-printable character which must be displayed
-                 either as '\003' or as `^C' where the '\\' and '^'
-                 can be defined in the display table.  Fill
+              /* C is a control character, non-ASCII space/hyphen,
+                 raw-byte, or a non-printable character which must be
+                 displayed either as '\003' or as `^C' where the '\\'
+                 and '^' can be defined in the display table.  Fill
                  IT->ctl_chars with glyphs for what we have to
                  display.  Then, set IT->dpvec to these glyphs.  */
               Lisp_Object gc;
@@ -6502,17 +6509,14 @@ get_next_display_element (struct it *it)
                   goto display_control;
                 }
 
-              /* Handle non-break space in the mode where it only gets
+              /* Handle non-ascii space in the mode where it only gets
                  highlighting.  */
 
-              if (EQ (Vnobreak_char_display, Qt)
-                  && nbsp_or_shy == char_is_nbsp)
+              if (nonascii_space_p && EQ (Vnobreak_char_display, Qt))
                 {
-                  /* Merge the no-break-space face into the current face.  */
+                  /* Merge `nobreak-space' into the current face.  */
                   face_id = merge_faces (it->f, Qnobreak_space, 0,
                                          it->face_id);
-
-                  c = ' ';
                   XSETINT (it->ctl_chars[0], ' ');
                   ctl_len = 1;
                   goto display_control;
@@ -6552,25 +6556,21 @@ get_next_display_element (struct it *it)
                   last_escape_glyph_merged_face_id = face_id;
                 }
 
-              /* Handle soft hyphens in the mode where they only get
-                 highlighting.  */
+              /* Draw non-ASCII hyphen with just highlighting: */
 
-              if (EQ (Vnobreak_char_display, Qt)
-                  && nbsp_or_shy == char_is_soft_hyphen)
+              if (nonascii_hyphen_p && EQ (Vnobreak_char_display, Qt))
                 {
                   XSETINT (it->ctl_chars[0], '-');
                   ctl_len = 1;
                   goto display_control;
                 }
 
-              /* Handle non-break space and soft hyphen
-                 with the escape glyph.  */
+              /* Draw non-ASCII space/hyphen with escape glyph: */
 
-              if (nbsp_or_shy)
+              if (nonascii_space_p || nonascii_hyphen_p)
                 {
                   XSETINT (it->ctl_chars[0], escape_glyph);
-                  c = (nbsp_or_shy == char_is_nbsp ? ' ' : '-');
-                  XSETINT (it->ctl_chars[1], c);
+                  XSETINT (it->ctl_chars[1], nonascii_space_p ? ' ' : '-');
                   ctl_len = 2;
                   goto display_control;
                 }
@@ -28001,12 +28001,18 @@ The face used for trailing whitespace is `trailing-whitespace'.  */);
   Vshow_trailing_whitespace = Qnil;
 
   DEFVAR_LISP ("nobreak-char-display", Vnobreak_char_display,
-    doc: /* *Control highlighting of nobreak space and soft hyphen.
-A value of t means highlight the character itself (for nobreak space,
-use face `nobreak-space').
-A value of nil means no highlighting.
-Other values mean display the escape glyph followed by an ordinary
-space or ordinary hyphen.  */);
+    doc: /* Control highlighting of non-ASCII space and hyphen chars.
+If the value is t, Emacs highlights non-ASCII chars which have the
+same appearance as an ASCII space or hyphen, using the `nobreak-space'
+or `escape-glyph' face respectively.
+
+U+00A0 (no-break space), U+00AD (soft hyphen), U+2010 (hyphen), and
+U+2011 (non-breaking hyphen) are affected.
+
+Any other non-nil value means to display these characters as a escape
+glyph followed by an ordinary space or hyphen.
+
+A value of nil means no special handling of these characters.  */);
   Vnobreak_char_display = Qt;
 
   DEFVAR_LISP ("void-text-area-pointer", Vvoid_text_area_pointer,