Make display strings obey buffer-invisibility-spec.

* src/xdisp.c (handle_invisible_prop): Obey TEXT_PROP_MEANS_INVISIBLE
for the string case.

* redisplay-testsuite.el (test-redisplay-4): New test.

Fixes: debbugs:3874

2 files changed, 37 insertions, 15 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 28143d43b23..beb47d6c998 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2012-08-18  Chong Yidong  <cyd@gnu.org>
+
+        * xdisp.c (handle_invisible_prop): Obey TEXT_PROP_MEANS_INVISIBLE
+        for the string case (Bug#3874).
+
 2012-08-18  Paul Eggert  <eggert@cs.ucla.edu>
 
         * buffer.h (BSET): Remove (Bug#12215).
diff --git a/src/xdisp.c b/src/xdisp.c
index 03fb94ca1b3..ff74af98304 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -4069,38 +4069,56 @@ static enum prop_handled
 handle_invisible_prop (struct it *it)
 {
   enum prop_handled handled = HANDLED_NORMALLY;
+  int invis_p;
+  Lisp_Object prop;
 
   if (STRINGP (it->string))
     {
-      Lisp_Object prop, end_charpos, limit, charpos;
+      Lisp_Object end_charpos, limit, charpos;
 
       /* Get the value of the invisible text property at the
          current position.  Value will be nil if there is no such
          property.  */
       charpos = make_number (IT_STRING_CHARPOS (*it));
       prop = Fget_text_property (charpos, Qinvisible, it->string);
+      invis_p = TEXT_PROP_MEANS_INVISIBLE (prop);
 
-      if (!NILP (prop)
-          && IT_STRING_CHARPOS (*it) < it->end_charpos)
+      if (invis_p && IT_STRING_CHARPOS (*it) < it->end_charpos)
         {
+          /* Record whether we have to display an ellipsis for the
+             invisible text.  */
+          int display_ellipsis_p = (invis_p == 2);
           ptrdiff_t endpos;
 
           handled = HANDLED_RECOMPUTE_PROPS;
 
-          /* Get the position at which the next change of the
-             invisible text property can be found in IT->string.
-             Value will be nil if the property value is the same for
-             all the rest of IT->string.  */
+          /* Get the position at which the next visible text can be
+             found in IT->string, if any.  */
           XSETINT (limit, SCHARS (it->string));
-          end_charpos = Fnext_single_property_change (charpos, Qinvisible,
-                                                      it->string, limit);
+          do
+            {
+              end_charpos = Fnext_single_property_change (charpos, Qinvisible,
+                                                          it->string, limit);
+              if (!NILP (end_charpos))
+                {
+                  prop = Fget_text_property (end_charpos, Qinvisible, it->string);
+                  invis_p = TEXT_PROP_MEANS_INVISIBLE (prop);
+                  if (invis_p == 2)
+                    display_ellipsis_p = 1;
+                }
+            }
+          while (!NILP (end_charpos) && invis_p);
+
+          if (display_ellipsis_p)
+            {
+              it->ellipsis_p = 1;
+              handled = HANDLED_RETURN;
+            }
 
-          /* Text at current position is invisible.  The next
-             change in the property is at position end_charpos.
-             Move IT's current position to that position.  */
           if (INTEGERP (end_charpos)
               && (endpos = XFASTINT (end_charpos)) < XFASTINT (limit))
             {
+              /* Text at END_CHARPOS is visible.  Move IT there.  */
               struct text_pos old;
               ptrdiff_t oldpos;
 
@@ -4153,9 +4171,8 @@ handle_invisible_prop (struct it *it)
     }
   else
     {
-      int invis_p;
       ptrdiff_t newpos, next_stop, start_charpos, tem;
-      Lisp_Object pos, prop, overlay;
+      Lisp_Object pos, overlay;
 
       /* First of all, is there invisible text at this position?  */
       tem = start_charpos = IT_CHARPOS (*it);
@@ -6032,7 +6049,7 @@ back_to_previous_visible_line_start (struct it *it)
       {
         Lisp_Object prop;
         prop = Fget_char_property (make_number (IT_CHARPOS (*it) - 1),
-                                     Qinvisible, it->window);
+                                   Qinvisible, it->window);
         if (TEXT_PROP_MEANS_INVISIBLE (prop))
           continue;
       }