1 files changed, 90 insertions, 22 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 31a82fefd78..a7ce6159a01 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -350,6 +350,10 @@ Lisp_Object Qtrailing_whitespace;
 
 Lisp_Object Qescape_glyph;
 
+/* Name and number of the face used to highlight non-breaking spaces.  */
+
+Lisp_Object Qno_break_space;
+
 /* The symbol `image' which is the car of the lists used to represent
    images in Lisp.  */
 
@@ -1881,7 +1885,7 @@ get_phys_cursor_geometry (w, row, glyph, heightp)
      int *heightp;
 {
   struct frame *f = XFRAME (WINDOW_FRAME (w));
-  int x, y, wd, h, h0, y0;
+  int y, wd, h, h0, y0;
 
   /* Compute the width of the rectangle to draw.  If on a stretch
      glyph, and `x-stretch-block-cursor' is nil, don't draw a
@@ -5081,8 +5085,10 @@ get_next_display_element (it)
                            && it->len == 1)
                           || !CHAR_PRINTABLE_P (it->c)
                           || (!NILP (Vshow_nonbreak_escape)
-                              && (it->c == 0x8ad || it->c == 0x8a0
-                                  || it->c == 0xf2d || it->c == 0xf20)))
+                              && (it->c == 0x8a0 || it->c == 0x8ad
+                                  || it->c == 0x920 || it->c == 0x92d
+                                  || it->c == 0xe20 || it->c == 0xe2d
+                                  || it->c == 0xf20 || it->c == 0xf2d)))
                        : (it->c >= 127
                           && (!unibyte_display_via_language_environment
                               || it->c == unibyte_char_to_multibyte (it->c)))))
@@ -5097,6 +5103,8 @@ get_next_display_element (it)
               int face_id, lface_id = 0 ;
               GLYPH escape_glyph;
 
+              /* Handle control characters with ^.  */
+
               if (it->c < 128 && it->ctl_arrow_p)
                 {
                   g = '^';           /* default glyph for Control */
@@ -5128,7 +5136,28 @@ get_next_display_element (it)
                   goto display_control;
                 }
 
-              escape_glyph = '\\';    /* default for Octal display */
+              /* Handle non-break space in the mode where it only gets
+                 highlighting.  */
+
+              if (! EQ (Vshow_nonbreak_escape, Qt)
+                  && (it->c == 0x8a0 || it->c == 0x920
+                      || it->c == 0xe20 || it->c == 0xf20))
+                {
+                  /* Merge the no-break-space face into the current face.  */
+                  face_id = merge_faces (it->f, Qno_break_space, 0,
+                                         it->face_id);
+
+                  g = it->c = ' ';
+                  XSETINT (it->ctl_chars[0], g);
+                  ctl_len = 1;
+                  goto display_control;
+                }
+
+              /* Handle sequences that start with the "escape glyph".  */
+
+              /* the default escape glyph is \.  */
+              escape_glyph = '\\';
+
               if (it->dp
                   && INTEGERP (DISP_ESCAPE_GLYPH (it->dp))
                   && GLYPH_CHAR_VALID_P (XFASTINT (DISP_ESCAPE_GLYPH (it->dp))))
@@ -5138,6 +5167,8 @@ get_next_display_element (it)
                 }
               if (lface_id)
                 {
+                  /* The display table specified a face.
+                     Merge it into face_id and also into escape_glyph.  */
                   escape_glyph = FAST_GLYPH_CHAR (escape_glyph);
                   face_id = merge_faces (it->f, Qt, lface_id,
                                          it->face_id);
@@ -5149,11 +5180,29 @@ get_next_display_element (it)
                                          it->face_id);
                 }
 
+              /* Handle soft hyphens in the mode where they only get
+                 highlighting.  */
+
+              if (! EQ (Vshow_nonbreak_escape, Qt)
+                  && (it->c == 0x8ad || it->c == 0x92d
+                      || it->c == 0xe2d || it->c == 0xf2d))
+                {
+                  g = it->c = '-';
+                  XSETINT (it->ctl_chars[0], g);
+                  ctl_len = 1;
+                  goto display_control;
+                }
+
+              /* Handle non-break space and soft hyphen
+                 with the escape glyph.  */
+
               if (it->c == 0x8a0 || it->c == 0x8ad
+                  || it->c == 0x920 || it->c == 0x92d
+                  || it->c == 0xe20 || it->c == 0xe2d
                   || it->c == 0xf20 || it->c == 0xf2d)
                 {
                   XSETINT (it->ctl_chars[0], escape_glyph);
-                  g = it->c;
+                  g = it->c = ((it->c & 0xf) == 0 ? ' ' : '-');
                   XSETINT (it->ctl_chars[1], g);
                   ctl_len = 2;
                   goto display_control;
@@ -8205,7 +8254,6 @@ static Lisp_Object
 format_mode_line_unwind_data (obuf)
      struct buffer *obuf;
 {
-  int i = 0;
   Lisp_Object vector;
 
   /* Reduce consing by keeping one vector in
@@ -8442,7 +8490,7 @@ prepare_menu_bars ()
       Lisp_Object tail, frame;
       int count = SPECPDL_INDEX ();
 
-      record_unwind_protect (Fset_match_data, Fmatch_data (Qnil, Qnil));
+      record_unwind_save_match_data ();
 
       FOR_EACH_FRAME (tail, frame)
         {
@@ -8565,7 +8613,7 @@ update_menu_bar (f, save_match_data)
 
           set_buffer_internal_1 (XBUFFER (w->buffer));
           if (save_match_data)
-            record_unwind_protect (Fset_match_data, Fmatch_data (Qnil, Qnil));
+            record_unwind_save_match_data ();
           if (NILP (Voverriding_local_map_menu_flag))
             {
               specbind (Qoverriding_terminal_local_map, Qnil);
@@ -8756,7 +8804,7 @@ update_tool_bar (f, save_match_data)
 
           /* Save match data, if we must.  */
           if (save_match_data)
-            record_unwind_protect (Fset_match_data, Fmatch_data (Qnil, Qnil));
+            record_unwind_save_match_data ();
 
           /* Make sure that we don't accidentally use bogus keymaps.  */
           if (NILP (Voverriding_local_map_menu_flag))
@@ -19160,7 +19208,7 @@ get_line_height_property (it, prop)
      struct it *it;
      Lisp_Object prop;
 {
-  Lisp_Object position, val;
+  Lisp_Object position;
 
   if (STRINGP (it->object))
     position = make_number (IT_STRING_CHARPOS (*it));
@@ -19511,7 +19559,6 @@ x_produce_glyphs (it)
           else
             {
               Lisp_Object spacing;
-              int total = 0;
 
               it->phys_ascent = it->ascent;
               it->phys_descent = it->descent;
@@ -21480,9 +21527,7 @@ note_mode_line_or_margin_highlight (window, x, y, area)
           int total_pixel_width;
           int ignore;
 
-
-          if (clear_mouse_face (dpyinfo))
-            cursor = No_Cursor;
+          int vpos, hpos;
 
           b = Fprevious_single_property_change (make_number (charpos + 1),
                                                 Qmouse_face, string, Qnil);
@@ -21526,15 +21571,30 @@ note_mode_line_or_margin_highlight (window, x, y, area)
           for (tmp_glyph = glyph - gpos; tmp_glyph != glyph; tmp_glyph++)
             total_pixel_width += tmp_glyph->pixel_width;
 
-          dpyinfo->mouse_face_beg_col = (x - gpos);
-          dpyinfo->mouse_face_beg_row = (area == ON_MODE_LINE
-                                         ? (w->current_matrix)->nrows - 1
-                                         : 0);
+          /* Pre calculation of re-rendering position */
+          vpos = (x - gpos);
+          hpos = (area == ON_MODE_LINE
+                  ? (w->current_matrix)->nrows - 1
+                  : 0);
+
+          /* If the re-rendering position is included in the last
+             re-rendering area, we should do nothing. */
+          if ( EQ (window, dpyinfo->mouse_face_window)
+               && dpyinfo->mouse_face_beg_col <= vpos
+               && vpos < dpyinfo->mouse_face_end_col
+               && dpyinfo->mouse_face_beg_row == hpos )
+            return;
+
+          if (clear_mouse_face (dpyinfo))
+            cursor = No_Cursor;
+
+          dpyinfo->mouse_face_beg_col = vpos;
+          dpyinfo->mouse_face_beg_row = hpos;
 
           dpyinfo->mouse_face_beg_x   = original_x_pixel - (total_pixel_width + dx);
           dpyinfo->mouse_face_beg_y   = 0;
 
-          dpyinfo->mouse_face_end_col = (x - gpos) + gseq_length;
+          dpyinfo->mouse_face_end_col = vpos + gseq_length;
           dpyinfo->mouse_face_end_row = dpyinfo->mouse_face_beg_row;
 
           dpyinfo->mouse_face_end_x   = 0;
@@ -21552,8 +21612,9 @@ note_mode_line_or_margin_highlight (window, x, y, area)
           if (NILP (pointer))
             pointer = Qhand;
         }
+      else if ((area == ON_MODE_LINE) || (area == ON_HEADER_LINE))
+        clear_mouse_face (dpyinfo);
     }
-
   define_frame_cursor1 (f, cursor, pointer);
 }
 
@@ -21606,7 +21667,8 @@ note_mouse_highlight (f, x, y)
   /* If we were displaying active text in another window, clear that.
      Also clear if we move out of text area in same window.  */
   if (! EQ (window, dpyinfo->mouse_face_window)
-      || (part != ON_TEXT && !NILP (dpyinfo->mouse_face_window)))
+      || (part != ON_TEXT && part != ON_MODE_LINE && part != ON_HEADER_LINE 
+          && !NILP (dpyinfo->mouse_face_window)))
     clear_mouse_face (dpyinfo);
 
   /* Not on a window -> return.  */
@@ -22723,6 +22785,8 @@ syms_of_xdisp ()
   staticpro (&Qtrailing_whitespace);
   Qescape_glyph = intern ("escape-glyph");
   staticpro (&Qescape_glyph);
+  Qno_break_space = intern ("no-break-space");
+  staticpro (&Qno_break_space);
   Qimage = intern ("image");
   staticpro (&Qimage);
   QCmap = intern (":map");
@@ -22829,7 +22893,11 @@ The face used for trailing whitespace is `trailing-whitespace'.  */);
   Vshow_trailing_whitespace = Qnil;
 
   DEFVAR_LISP ("show-nonbreak-escape", &Vshow_nonbreak_escape,
-    doc: /* *Non-nil means display escape character before non-break space and hyphen.  */);
+    doc: /* *Control highlighting of non-break space and soft hyphen.
+t means highlight the character itself (for non-break space,
+use face `non-break-space'.
+nil means no highlighting.
+other values mean display the escape glyph before the character.  */);
   Vshow_nonbreak_escape = Qt;
 
   DEFVAR_LISP ("void-text-area-pointer", &Vvoid_text_area_pointer,