For line prefixes, use default face; don't inherit from previous line.

* src/dispextern.h (struct it): New member string_from_prefix_prop_p.

* src/xdisp.c (push_prefix_prop): Renamed from push_display_prop.
Mark string as coming from a prefix property.
(handle_face_prop): Use default face for prefix strings.
(pop_it, reseat_1): Save and restore string_from_prefix_prop_p.

Fixes: debbugs:4281

3 files changed, 24 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 7a97859ba63..e3407a45514 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,12 @@
+2012-03-22  Chong Yidong  <cyd@gnu.org>
+
+        * dispextern.h (struct it): New member string_from_prefix_prop_p.
+
+        * xdisp.c (push_prefix_prop): Renamed from push_display_prop.
+        Mark string as coming from a prefix property.
+        (handle_face_prop): Use default face for prefix strings (Bug#4281).
+        (pop_it, reseat_1): Save and restore string_from_prefix_prop_p.
+
 2012-03-21  Chong Yidong  <cyd@gnu.org>
 
         * xfaces.c (Vface_remapping_alist): Doc fix.
diff --git a/src/dispextern.h b/src/dispextern.h
index 2c59f4f8ead..2d4aee0cb94 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -2152,6 +2152,10 @@ struct it
      Don't handle some `display' properties in these strings.  */
   unsigned string_from_display_prop_p : 1;
 
+  /* 1 means `string' comes from a `line-prefix' or `wrap-prefix'
+     property.  */
+  unsigned string_from_prefix_prop_p : 1;
+
   /* 1 means we are iterating an object that came from a value of a
      `display' property.  */
   unsigned from_disp_prop_p : 1;
@@ -2272,6 +2276,7 @@ struct it
     bidi_dir_t paragraph_embedding;
     unsigned multibyte_p : 1;
     unsigned string_from_display_prop_p : 1;
+    unsigned string_from_prefix_prop_p : 1;
     unsigned display_ellipsis_p : 1;
     unsigned avoid_cursor_p : 1;
     unsigned bidi_p:1;
diff --git a/src/xdisp.c b/src/xdisp.c
index 71162960faa..0d23d72dd7b 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -3673,7 +3673,9 @@ handle_face_prop (struct it *it)
              with, so that overlay strings appear in the same face as
              surrounding text, unless they specify their own
              faces.  */
-          base_face_id = underlying_face_id (it);
+          base_face_id = it->string_from_prefix_prop_p
+            ? DEFAULT_FACE_ID
+            : underlying_face_id (it);
         }
 
       new_face_id = face_at_string_position (it->w,
@@ -5576,6 +5578,7 @@ push_it (struct it *it, struct text_pos *position)
   p->font_height = it->font_height;
   p->voffset = it->voffset;
   p->string_from_display_prop_p = it->string_from_display_prop_p;
+  p->string_from_prefix_prop_p = it->string_from_prefix_prop_p;
   p->display_ellipsis_p = 0;
   p->line_wrap = it->line_wrap;
   p->bidi_p = it->bidi_p;
@@ -5685,6 +5688,7 @@ pop_it (struct it *it)
   it->font_height = p->font_height;
   it->voffset = p->voffset;
   it->string_from_display_prop_p = p->string_from_display_prop_p;
+  it->string_from_prefix_prop_p = p->string_from_prefix_prop_p;
   it->line_wrap = p->line_wrap;
   it->bidi_p = p->bidi_p;
   it->paragraph_embedding = p->paragraph_embedding;
@@ -6115,6 +6119,8 @@ reseat_1 (struct it *it, struct text_pos pos, int set_stop_p)
   it->multibyte_p = !NILP (BVAR (current_buffer, enable_multibyte_characters));
   it->sp = 0;
   it->string_from_display_prop_p = 0;
+  it->string_from_prefix_prop_p = 0;
+
   it->from_disp_prop_p = 0;
   it->face_before_selective_p = 0;
   if (it->bidi_p)
@@ -18539,7 +18545,7 @@ cursor_row_p (struct glyph_row *row)
    `line-prefix' and `wrap-prefix' properties.  */
 
 static int
-push_display_prop (struct it *it, Lisp_Object prop)
+push_prefix_prop (struct it *it, Lisp_Object prop)
 {
   struct text_pos pos =
     STRINGP (it->string) ? it->current.string_pos : it->current.pos;
@@ -18563,6 +18569,7 @@ push_display_prop (struct it *it, Lisp_Object prop)
         }
 
       it->string = prop;
+      it->string_from_prefix_prop_p = 1;
       it->multibyte_p = STRING_MULTIBYTE (it->string);
       it->current.overlay_string_index = -1;
       IT_STRING_CHARPOS (*it) = IT_STRING_BYTEPOS (*it) = 0;
@@ -18649,7 +18656,7 @@ handle_line_prefix (struct it *it)
       if (NILP (prefix))
         prefix = Vline_prefix;
     }
-  if (! NILP (prefix) && push_display_prop (it, prefix))
+  if (! NILP (prefix) && push_prefix_prop (it, prefix))
     {
       /* If the prefix is wider than the window, and we try to wrap
          it, it would acquire its own wrap prefix, and so on till the