Handle `(space ...)' display spec as paragraph separator.

[bpt/emacs.git] / src / xdisp.c

diff --git a/src/xdisp.c b/src/xdisp.c
index 4ed08e7..5cbc774 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -3146,11 +3146,15 @@ next_overlay_change (EMACS_INT pos)
    text property whose value is a string.  STRING is data about the
    string to iterate; if STRING->lstring is nil, we are iterating a
    buffer.  FRAME_WINDOW_P is non-zero when we are displaying a window
-   on a GUI frame.  */
+   on a GUI frame.  DISP_PROP is set to zero if we searched
+   MAX_DISP_SCAN characters forward without finding any display
+   strings, non-zero otherwise.  It is set to 2 if the display string
+   uses any kind of `(space ...)' spec that will produce a stretch of
+   white space in the text area.  */
 EMACS_INT
 compute_display_string_pos (struct text_pos *position,
                            struct bidi_string_data *string,
-                           int frame_window_p, int *disp_prop_p)
+                           int frame_window_p, int *disp_prop)
 {
   /* OBJECT = nil means current buffer.  */
   Lisp_Object object =
@@ -3163,8 +3167,9 @@ compute_display_string_pos (struct text_pos *position,
   EMACS_INT lim =
     (charpos < eob - MAX_DISP_SCAN) ? charpos + MAX_DISP_SCAN : eob;
   struct text_pos tpos;
+  int rv = 0;
 
-  *disp_prop_p = 1;
+  *disp_prop = 1;
 
   if (charpos >= eob
       /* We don't support display properties whose values are strings
@@ -3173,7 +3178,7 @@ compute_display_string_pos (struct text_pos *position,
       /* C strings cannot have display properties.  */
       || (string->s && !STRINGP (object)))
     {
-      *disp_prop_p = 0;
+      *disp_prop = 0;
       return eob;
     }
 
@@ -3190,9 +3195,11 @@ compute_display_string_pos (struct text_pos *position,
          || !EQ (Fget_char_property (make_number (charpos - 1), Qdisplay,
                                      object),
                  spec))
-      && handle_display_spec (NULL, spec, object, Qnil, &tpos, bufpos,
-                             frame_window_p))
+      && (rv = handle_display_spec (NULL, spec, object, Qnil, &tpos, bufpos,
+                                   frame_window_p)))
     {
+      if (rv == 2)
+       *disp_prop = 2;
       return charpos;
     }
 
@@ -3204,7 +3211,7 @@ compute_display_string_pos (struct text_pos *position,
     CHARPOS (tpos) = XFASTINT (pos);
     if (CHARPOS (tpos) >= lim)
       {
-       *disp_prop_p = 0;
+       *disp_prop = 0;
        break;
       }
     if (STRINGP (object))
@@ -3215,8 +3222,10 @@ compute_display_string_pos (struct text_pos *position,
     if (!STRINGP (object))
       bufpos = CHARPOS (tpos);
   } while (NILP (spec)
-          || !handle_display_spec (NULL, spec, object, Qnil, &tpos, bufpos,
-                                   frame_window_p));
+          || !(rv = handle_display_spec (NULL, spec, object, Qnil, &tpos,
+                                         bufpos, frame_window_p)));
+  if (rv == 2)
+    *disp_prop = 2;
 
   return CHARPOS (tpos);
 }
@@ -4078,7 +4087,9 @@ handle_display_prop (struct it *it)
 /* Subroutine of handle_display_prop.  Returns non-zero if the display
    specification in SPEC is a replacing specification, i.e. it would
    replace the text covered by `display' property with something else,
-   such as an image or a display string.
+   such as an image or a display string.  If SPEC includes any kind or
+   `(space ...) specification, the value is 2; this is used by
+   compute_display_string_pos, which see.
 
    See handle_single_display_spec for documentation of arguments.
    frame_window_p is non-zero if the window being redisplayed is on a
@@ -4095,6 +4106,7 @@ handle_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
                     EMACS_INT bufpos, int frame_window_p)
 {
   int replacing_p = 0;
+  int rv;
 
   if (CONSP (spec)
       /* Simple specerties.  */
@@ -4113,11 +4125,11 @@ handle_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
     {
       for (; CONSP (spec); spec = XCDR (spec))
        {
-         if (handle_single_display_spec (it, XCAR (spec), object, overlay,
-                                         position, bufpos, replacing_p,
-                                         frame_window_p))
+         if ((rv = handle_single_display_spec (it, XCAR (spec), object,
+                                               overlay, position, bufpos,
+                                               replacing_p, frame_window_p)))
            {
-             replacing_p = 1;
+             replacing_p = rv;
              /* If some text in a string is replaced, `position' no
                 longer points to the position of `object'.  */
              if (!it || STRINGP (object))
@@ -4129,11 +4141,11 @@ handle_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
     {
       int i;
       for (i = 0; i < ASIZE (spec); ++i)
-       if (handle_single_display_spec (it, AREF (spec, i), object, overlay,
-                                       position, bufpos, replacing_p,
-                                       frame_window_p))
+       if ((rv = handle_single_display_spec (it, AREF (spec, i), object,
+                                             overlay, position, bufpos,
+                                             replacing_p, frame_window_p)))
          {
-           replacing_p = 1;
+           replacing_p = rv;
            /* If some text in a string is replaced, `position' no
               longer points to the position of `object'.  */
            if (!it || STRINGP (object))
@@ -4142,9 +4154,10 @@ handle_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
     }
   else
     {
-      if (handle_single_display_spec (it, spec, object, overlay,
-                                     position, bufpos, 0, frame_window_p))
-       replacing_p = 1;
+      if ((rv = handle_single_display_spec (it, spec, object, overlay,
+                                           position, bufpos, 0,
+                                           frame_window_p)))
+       replacing_p = rv;
     }
 
   return replacing_p;
@@ -4520,8 +4533,17 @@ handle_single_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
 
   if (valid_p && !display_replaced_p)
     {
+      int retval = 1;
+
       if (!it)
-       return 1;
+       {
+         /* Callers need to know whether the display spec is any kind
+            of `(space ...)' spec that is about to affect text-area
+            display.  */
+         if (CONSP (value) && EQ (XCAR (value), Qspace) && NILP (location))
+           retval = 2;
+         return retval;
+       }
 
       /* Save current settings of IT so that we can restore them
         when we are finished with the glyph property value.  */
@@ -4579,6 +4601,7 @@ handle_single_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
          it->method = GET_FROM_STRETCH;
          it->object = value;
          *position = it->position = start_pos;
+         retval = 1 + (it->area == TEXT_AREA);
        }
 #ifdef HAVE_WINDOW_SYSTEM
       else
@@ -4596,7 +4619,7 @@ handle_single_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
        }
 #endif /* HAVE_WINDOW_SYSTEM */
 
-      return 1;
+      return retval;
     }
 
   /* Invalid property or property not supported.  Restore
@@ -5557,7 +5580,7 @@ forward_to_next_line_start (struct it *it, int *skipped_p,
              if (it->bidi_it.disp_pos < limit)
                {
                  it->bidi_it.disp_pos = limit;
-                 it->bidi_it.disp_prop_p = 0;
+                 it->bidi_it.disp_prop = 0;
                }
              do {
                bprev = it->bidi_it;