Inline functions to examine and change buffer overlays.

* buffer.c (unchain_both): New function.
* buffer.h (buffer_get_overlays, buffer_set_overlays):
(buffer_has_overlays): New function.
(enum overlay_type): New enum.
* alloc.c, buffer.c, editfns.c, fileio.c, indent.c:
* insdel.c, intervals.c, print.c, xdisp.c: Adjust users.

11 files changed, 144 insertions, 77 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9c6d4b4458d..3717b4400b2 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,15 @@
 2012-08-08  Dmitry Antipov  <dmantipov@yandex.ru>
 
+        Inline functions to examine and change buffer overlays.
+        * buffer.c (unchain_both): New function.
+        * buffer.h (buffer_get_overlays, buffer_set_overlays):
+        (buffer_has_overlays): New function.
+        (enum overlay_type): New enum.
+        * alloc.c, buffer.c, editfns.c, fileio.c, indent.c:
+        * insdel.c, intervals.c, print.c, xdisp.c: Adjust users.
+
+2012-08-08  Dmitry Antipov  <dmantipov@yandex.ru>
+
         Inline functions to examine and change buffer intervals.
         * alloc.c (mark_interval_tree): Remove.
         (MARK_INTERVAL_TREE): Simplify.
diff --git a/src/alloc.c b/src/alloc.c
index c93fcb564c7..e84be987033 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5831,8 +5831,8 @@ mark_buffer (struct buffer *buffer)
      a special way just before the sweep phase, and after stripping
      some of its elements that are not needed any more.  */
 
-  mark_overlay (buffer->overlays_before);
-  mark_overlay (buffer->overlays_after);
+  mark_overlay (buffer_get_overlays (buffer, OV_BEFORE));
+  mark_overlay (buffer_get_overlays (buffer, OV_AFTER));
 
   /* If this is an indirect buffer, mark its base buffer.  */
   if (buffer->base_buffer && !VECTOR_MARKED_P (buffer->base_buffer))
diff --git a/src/buffer.c b/src/buffer.c
index fab7330b195..6b68f34bb15 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -474,8 +474,10 @@ clone_per_buffer_values (struct buffer *from, struct buffer *to)
 
   memcpy (to->local_flags, from->local_flags, sizeof to->local_flags);
 
-  to->overlays_before = copy_overlays (to, from->overlays_before);
-  to->overlays_after = copy_overlays (to, from->overlays_after);
+  buffer_set_overlays
+    (to, copy_overlays (to, buffer_get_overlays (from, OV_BEFORE)), OV_BEFORE);
+  buffer_set_overlays
+    (to, copy_overlays (to, buffer_get_overlays (from, OV_AFTER)), OV_AFTER);
 
   /* Get (a copy of) the alist of Lisp-level local variables of FROM
      and install that in TO.  */
@@ -674,21 +676,22 @@ delete_all_overlays (struct buffer *b)
 {
   struct Lisp_Overlay *ov, *next;
 
-  for (ov = b->overlays_before; ov; ov = next)
+  for (ov = buffer_get_overlays (b, OV_BEFORE); ov; ov = next)
     {
       drop_overlay (b, ov);
       next = ov->next;
       ov->next = NULL;
     }
 
-  for (ov = b->overlays_after; ov; ov = next)
+  for (ov = buffer_get_overlays (b, OV_AFTER); ov; ov = next)
     {
       drop_overlay (b, ov);
       next = ov->next;
       ov->next = NULL;
     }
 
-  b->overlays_before = b->overlays_after = NULL;
+  buffer_set_overlays (b, NULL, OV_BEFORE);
+  buffer_set_overlays (b, NULL, OV_AFTER);
 }
 
 /* Reinitialize everything about a buffer except its name and contents
@@ -716,8 +719,8 @@ reset_buffer (register struct buffer *b)
   b->auto_save_failure_time = 0;
   BVAR (b, auto_save_file_name) = Qnil;
   BVAR (b, read_only) = Qnil;
-  b->overlays_before = NULL;
-  b->overlays_after = NULL;
+  buffer_set_overlays (b, NULL, OV_BEFORE);
+  buffer_set_overlays (b, NULL, OV_AFTER);
   b->overlay_center = BEG;
   BVAR (b, mark_active) = Qnil;
   BVAR (b, point_before_scroll) = Qnil;
@@ -2602,7 +2605,7 @@ overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
   ptrdiff_t prev = BEGV;
   int inhibit_storing = 0;
 
-  for (tail = current_buffer->overlays_before; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_BEFORE); tail; tail = tail->next)
     {
       ptrdiff_t startpos, endpos;
 
@@ -2650,7 +2653,7 @@ overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
         next = startpos;
     }
 
-  for (tail = current_buffer->overlays_after; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_AFTER); tail; tail = tail->next)
     {
       ptrdiff_t startpos, endpos;
 
@@ -2737,7 +2740,7 @@ overlays_in (EMACS_INT beg, EMACS_INT end, int extend,
   int inhibit_storing = 0;
   int end_is_Z = end == Z;
 
-  for (tail = current_buffer->overlays_before; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_BEFORE); tail; tail = tail->next)
     {
       ptrdiff_t startpos, endpos;
 
@@ -2784,7 +2787,7 @@ overlays_in (EMACS_INT beg, EMACS_INT end, int extend,
         next = startpos;
     }
 
-  for (tail = current_buffer->overlays_after; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_AFTER); tail; tail = tail->next)
     {
       ptrdiff_t startpos, endpos;
 
@@ -2874,7 +2877,7 @@ overlay_touches_p (ptrdiff_t pos)
   Lisp_Object overlay;
   struct Lisp_Overlay *tail;
 
-  for (tail = current_buffer->overlays_before; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_BEFORE); tail; tail = tail->next)
     {
       ptrdiff_t endpos;
 
@@ -2888,7 +2891,7 @@ overlay_touches_p (ptrdiff_t pos)
         return 1;
     }
 
-  for (tail = current_buffer->overlays_after; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_AFTER); tail; tail = tail->next)
     {
       ptrdiff_t startpos;
 
@@ -3089,7 +3092,7 @@ overlay_strings (ptrdiff_t pos, struct window *w, unsigned char **pstr)
 
   overlay_heads.used = overlay_heads.bytes = 0;
   overlay_tails.used = overlay_tails.bytes = 0;
-  for (ov = current_buffer->overlays_before; ov; ov = ov->next)
+  for (ov = buffer_get_overlays (NULL, OV_BEFORE); ov; ov = ov->next)
     {
       XSETMISC (overlay, ov);
       eassert (OVERLAYP (overlay));
@@ -3117,7 +3120,7 @@ overlay_strings (ptrdiff_t pos, struct window *w, unsigned char **pstr)
                                Foverlay_get (overlay, Qpriority),
                                endpos - startpos);
     }
-  for (ov = current_buffer->overlays_after; ov; ov = ov->next)
+  for (ov = buffer_get_overlays (NULL, OV_AFTER); ov; ov = ov->next)
     {
       XSETMISC (overlay, ov);
       eassert (OVERLAYP (overlay));
@@ -3215,7 +3218,7 @@ recenter_overlay_lists (struct buffer *buf, ptrdiff_t pos)
      But we use it for symmetry and in case that should cease to be true
      with some future change.  */
   prev = NULL;
-  for (tail = buf->overlays_before; tail; prev = tail, tail = next)
+  for (tail = buffer_get_overlays (buf, OV_BEFORE); tail; prev = tail, tail = next)
     {
       next = tail->next;
       XSETMISC (overlay, tail);
@@ -3234,11 +3237,11 @@ recenter_overlay_lists (struct buffer *buf, ptrdiff_t pos)
           if (prev)
             prev->next = next;
           else
-            buf->overlays_before = next;
+            buffer_set_overlays (buf, next, OV_BEFORE);
 
           /* Search thru overlays_after for where to put it.  */
           other_prev = NULL;
-          for (other = buf->overlays_after; other;
+          for (other = buffer_get_overlays (buf, OV_AFTER); other;
                other_prev = other, other = other->next)
             {
               Lisp_Object otherbeg, otheroverlay;
@@ -3256,7 +3259,7 @@ recenter_overlay_lists (struct buffer *buf, ptrdiff_t pos)
           if (other_prev)
             other_prev->next = tail;
           else
-            buf->overlays_after = tail;
+            buffer_set_overlays (buf, tail, OV_AFTER);
           tail = prev;
         }
       else
@@ -3268,7 +3271,7 @@ recenter_overlay_lists (struct buffer *buf, ptrdiff_t pos)
 
   /* See if anything in overlays_after should be in overlays_before.  */
   prev = NULL;
-  for (tail = buf->overlays_after; tail; prev = tail, tail = next)
+  for (tail = buffer_get_overlays (buf, OV_AFTER); tail; prev = tail, tail = next)
     {
       next = tail->next;
       XSETMISC (overlay, tail);
@@ -3292,11 +3295,11 @@ recenter_overlay_lists (struct buffer *buf, ptrdiff_t pos)
           if (prev)
             prev->next = next;
           else
-            buf->overlays_after = next;
+            buffer_set_overlays (buf, next, OV_AFTER);
 
           /* Search thru overlays_before for where to put it.  */
           other_prev = NULL;
-          for (other = buf->overlays_before; other;
+          for (other = buffer_get_overlays (buf, OV_BEFORE); other;
                other_prev = other, other = other->next)
             {
               Lisp_Object otherend, otheroverlay;
@@ -3314,7 +3317,7 @@ recenter_overlay_lists (struct buffer *buf, ptrdiff_t pos)
           if (other_prev)
             other_prev->next = tail;
           else
-            buf->overlays_before = tail;
+            buffer_set_overlays (buf, tail, OV_BEFORE);
           tail = prev;
         }
     }
@@ -3367,7 +3370,7 @@ fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
      assigned.  */
   struct Lisp_Overlay *beforep = NULL, *afterp = NULL;
   /* 'Parent', likewise, indicates a cons cell or
-     current_buffer->overlays_before or overlays_after, depending
+     before or after overlays list, depending
      which loop we're in.  */
   struct Lisp_Overlay *tail, *parent;
   ptrdiff_t startpos, endpos;
@@ -3379,7 +3382,7 @@ fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
      (after_list) if it is, is still uninitialized.  So it's not a bug
      that before_list isn't initialized, although it may look
      strange.  */
-  for (parent = NULL, tail = current_buffer->overlays_before; tail;)
+  for (parent = NULL, tail = buffer_get_overlays (NULL, OV_BEFORE); tail;)
     {
       XSETMISC (overlay, tail);
 
@@ -3419,7 +3422,7 @@ fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
               beforep = tail;
             }
           if (!parent)
-            current_buffer->overlays_before = tail->next;
+            buffer_set_overlays (NULL, tail->next, OV_BEFORE);
           else
             parent->next = tail->next;
           tail = tail->next;
@@ -3427,7 +3430,7 @@ fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
       else
         parent = tail, tail = parent->next;
     }
-  for (parent = NULL, tail = current_buffer->overlays_after; tail;)
+  for (parent = NULL, tail = buffer_get_overlays (NULL, OV_AFTER); tail;)
     {
       XSETMISC (overlay, tail);
 
@@ -3465,7 +3468,7 @@ fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
               beforep = tail;
             }
           if (!parent)
-            current_buffer->overlays_after = tail->next;
+            buffer_set_overlays (NULL, tail->next, OV_AFTER);
           else
             parent->next = tail->next;
           tail = tail->next;
@@ -3478,15 +3481,15 @@ fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
      and let the recenter function make it sane again.  */
   if (beforep)
     {
-      beforep->next = current_buffer->overlays_before;
-      current_buffer->overlays_before = before_list;
+      beforep->next = buffer_get_overlays (NULL, OV_BEFORE);
+      buffer_set_overlays (NULL, before_list, OV_BEFORE);
     }
   recenter_overlay_lists (current_buffer, current_buffer->overlay_center);
 
   if (afterp)
     {
-      afterp->next = current_buffer->overlays_after;
-      current_buffer->overlays_after = after_list;
+      afterp->next = buffer_get_overlays (NULL, OV_AFTER);
+      buffer_set_overlays (NULL, after_list, OV_AFTER);
     }
   recenter_overlay_lists (current_buffer, current_buffer->overlay_center);
 }
@@ -3507,7 +3510,8 @@ void
 fix_overlays_before (struct buffer *bp, ptrdiff_t prev, ptrdiff_t pos)
 {
   /* If parent is nil, replace overlays_before; otherwise, parent->next.  */
-  struct Lisp_Overlay *tail = bp->overlays_before, *parent = NULL, *right_pair;
+  struct Lisp_Overlay *tail = buffer_get_overlays (bp, OV_BEFORE);
+  struct Lisp_Overlay *parent = NULL, *right_pair;
   Lisp_Object tem;
   ptrdiff_t end IF_LINT (= 0);
 
@@ -3562,8 +3566,8 @@ fix_overlays_before (struct buffer *bp, ptrdiff_t prev, ptrdiff_t pos)
              and link it into the right place.  */
           if (!right_pair)
             {
-              found->next = bp->overlays_before;
-              bp->overlays_before = found;
+              found->next = buffer_get_overlays (bp, OV_BEFORE);
+              buffer_set_overlays (bp, found, OV_BEFORE);
             }
           else
             {
@@ -3639,15 +3643,15 @@ for the rear of the overlay advance when text is inserted there
   end = OVERLAY_END (overlay);
   if (OVERLAY_POSITION (end) < b->overlay_center)
     {
-      if (b->overlays_after)
-        XOVERLAY (overlay)->next = b->overlays_after;
-      b->overlays_after = XOVERLAY (overlay);
+      if (buffer_get_overlays (b, OV_AFTER))
+        XOVERLAY (overlay)->next = buffer_get_overlays (b, OV_AFTER);
+      buffer_set_overlays (b, XOVERLAY (overlay), OV_AFTER);
     }
   else
     {
-      if (b->overlays_before)
-        XOVERLAY (overlay)->next = b->overlays_before;
-      b->overlays_before = XOVERLAY (overlay);
+      if (buffer_get_overlays (b, OV_BEFORE))
+        XOVERLAY (overlay)->next = buffer_get_overlays (b, OV_BEFORE);
+      buffer_set_overlays (b, XOVERLAY (overlay), OV_BEFORE);
     }
 
   /* This puts it in the right list, and in the right order.  */
@@ -3705,6 +3709,19 @@ unchain_overlay (struct Lisp_Overlay *list, struct Lisp_Overlay *overlay)
   return list;
 }
 
+/* Remove OVERLAY from both overlay lists of B.  */
+
+static void
+unchain_both (struct buffer *b, Lisp_Object overlay)
+{
+  struct Lisp_Overlay *ov = XOVERLAY (overlay);
+
+  buffer_set_overlays 
+    (b, unchain_overlay (buffer_get_overlays (b, OV_BEFORE), ov), OV_BEFORE);
+  buffer_set_overlays
+    (b, unchain_overlay (buffer_get_overlays (b, OV_AFTER), ov), OV_AFTER);
+}
+
 DEFUN ("move-overlay", Fmove_overlay, Smove_overlay, 3, 4, 0,
        doc: /* Set the endpoints of OVERLAY to BEG and END in BUFFER.
 If BUFFER is omitted, leave OVERLAY in the same buffer it inhabits now.
@@ -3755,10 +3772,7 @@ buffer.  */)
       o_beg = OVERLAY_POSITION (OVERLAY_START (overlay));
       o_end = OVERLAY_POSITION (OVERLAY_END (overlay));
 
-      ob->overlays_before =
-        unchain_overlay (ob->overlays_before, XOVERLAY (overlay));
-      ob->overlays_after =
-        unchain_overlay (ob->overlays_after, XOVERLAY (overlay));
+      unchain_both (ob, overlay);
       eassert (XOVERLAY (overlay)->next == NULL);
     }
 
@@ -3799,13 +3813,13 @@ buffer.  */)
      wrong list.  */
   if (n_end < b->overlay_center)
     {
-      XOVERLAY (overlay)->next = b->overlays_after;
-      b->overlays_after = XOVERLAY (overlay);
+      XOVERLAY (overlay)->next = buffer_get_overlays (b, OV_AFTER);
+      buffer_set_overlays (b, XOVERLAY (overlay), OV_AFTER);
     }
   else
     {
-      XOVERLAY (overlay)->next = b->overlays_before;
-      b->overlays_before = XOVERLAY (overlay);
+      XOVERLAY (overlay)->next = buffer_get_overlays (b, OV_BEFORE);
+      buffer_set_overlays (b, XOVERLAY (overlay), OV_BEFORE);
     }
 
   /* This puts it in the right list, and in the right order.  */
@@ -3831,10 +3845,7 @@ DEFUN ("delete-overlay", Fdelete_overlay, Sdelete_overlay, 1, 1, 0,
   b = XBUFFER (buffer);
   specbind (Qinhibit_quit, Qt);
 
-  b->overlays_before
-    = unchain_overlay (b->overlays_before, XOVERLAY (overlay));
-  b->overlays_after
-    = unchain_overlay (b->overlays_after, XOVERLAY (overlay));
+  unchain_both (b, overlay);
   eassert (XOVERLAY (overlay)->next == NULL);
 
   drop_overlay (b, XOVERLAY (overlay));
@@ -4033,16 +4044,19 @@ However, the overlays you get are the real objects that the buffer uses.  */)
 {
   struct Lisp_Overlay *ol;
   Lisp_Object before = Qnil, after = Qnil, tmp;
-  for (ol = current_buffer->overlays_before; ol; ol = ol->next)
+
+  for (ol = buffer_get_overlays (NULL, OV_BEFORE); ol; ol = ol->next)
     {
       XSETMISC (tmp, ol);
       before = Fcons (tmp, before);
     }
-  for (ol = current_buffer->overlays_after; ol; ol = ol->next)
+
+  for (ol = buffer_get_overlays (NULL, OV_AFTER); ol; ol = ol->next)
     {
       XSETMISC (tmp, ol);
       after = Fcons (tmp, after);
     }
+
   return Fcons (Fnreverse (before), Fnreverse (after));
 }
 
@@ -4182,7 +4196,7 @@ report_overlay_modification (Lisp_Object start, Lisp_Object end, int after,
       /* We are being called before a change.
          Scan the overlays to find the functions to call.  */
       last_overlay_modification_hooks_used = 0;
-      for (tail = current_buffer->overlays_before; tail; tail = tail->next)
+      for (tail = buffer_get_overlays (NULL, OV_BEFORE); tail; tail = tail->next)
         {
           ptrdiff_t startpos, endpos;
           Lisp_Object ostart, oend;
@@ -4219,7 +4233,7 @@ report_overlay_modification (Lisp_Object start, Lisp_Object end, int after,
             }
         }
 
-      for (tail = current_buffer->overlays_after; tail; tail = tail->next)
+      for (tail = buffer_get_overlays (NULL, OV_AFTER); tail; tail = tail->next)
         {
           ptrdiff_t startpos, endpos;
           Lisp_Object ostart, oend;
@@ -4311,7 +4325,7 @@ evaporate_overlays (ptrdiff_t pos)
 
   hit_list = Qnil;
   if (pos <= current_buffer->overlay_center)
-    for (tail = current_buffer->overlays_before; tail; tail = tail->next)
+    for (tail = buffer_get_overlays (NULL, OV_BEFORE); tail; tail = tail->next)
       {
         ptrdiff_t endpos;
         XSETMISC (overlay, tail);
@@ -4323,7 +4337,7 @@ evaporate_overlays (ptrdiff_t pos)
           hit_list = Fcons (overlay, hit_list);
       }
   else
-    for (tail = current_buffer->overlays_after; tail; tail = tail->next)
+    for (tail = buffer_get_overlays (NULL, OV_AFTER); tail; tail = tail->next)
       {
         ptrdiff_t startpos;
         XSETMISC (overlay, tail);
diff --git a/src/buffer.h b/src/buffer.h
index 986df8e6d32..a52ca7193e4 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -945,6 +945,52 @@ extern void mmap_set_vars (int);
       }                                                                 \
   } while (0)
 
+enum overlay_type
+{
+  OV_BEFORE,
+  OV_AFTER
+};
+
+/* Get overlay list of type T and belonging to B.  */
+
+BUFFER_INLINE struct Lisp_Overlay *
+buffer_get_overlays (struct buffer *b, enum overlay_type t)
+{
+  if (!b)
+    b = current_buffer;
+  if (t == OV_BEFORE)
+    return b->overlays_before;
+  else if (t == OV_AFTER)
+    return b->overlays_after;
+  else
+    abort ();
+}
+
+/* Set overlay list of type T as belonging to B.  */
+
+BUFFER_INLINE void
+buffer_set_overlays (struct buffer *b, struct Lisp_Overlay *o,
+                     enum overlay_type t)
+{
+  if (!b)
+    b = current_buffer;
+  if (t == OV_BEFORE)
+    b->overlays_before = o;
+  else if (t == OV_AFTER)
+    b->overlays_after = o;
+  else
+    abort ();
+}
+
+/* Non-zero if current buffer has overlays.  */
+
+BUFFER_INLINE int
+buffer_has_overlays (void)
+{
+  return buffer_get_overlays (current_buffer, OV_BEFORE)
+    || buffer_get_overlays (current_buffer, OV_AFTER);
+}
+
 extern Lisp_Object Qbefore_change_functions;
 extern Lisp_Object Qafter_change_functions;
 extern Lisp_Object Qfirst_change_hook;
diff --git a/src/editfns.c b/src/editfns.c
index aca34482fb2..246e51cb0d5 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -310,7 +310,7 @@ overlays_around (EMACS_INT pos, Lisp_Object *vec, ptrdiff_t len)
   ptrdiff_t startpos, endpos;
   ptrdiff_t idx = 0;
 
-  for (tail = current_buffer->overlays_before; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_BEFORE); tail; tail = tail->next)
     {
       XSETMISC (overlay, tail);
 
@@ -329,7 +329,7 @@ overlays_around (EMACS_INT pos, Lisp_Object *vec, ptrdiff_t len)
         }
     }
 
-  for (tail = current_buffer->overlays_after; tail; tail = tail->next)
+  for (tail = buffer_get_overlays (NULL, OV_AFTER); tail; tail = tail->next)
     {
       XSETMISC (overlay, tail);
 
diff --git a/src/fileio.c b/src/fileio.c
index 9fe7437669c..886f9b9b103 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3490,8 +3490,8 @@ variable `last-coding-system-used' to the coding system actually used.  */)
                   BVAR (buf, read_only) = Qnil;
                   BVAR (buf, filename) = Qnil;
                   BVAR (buf, undo_list) = Qt;
-                  eassert (buf->overlays_before == NULL);
-                  eassert (buf->overlays_after == NULL);
+                  eassert (buffer_get_overlays (buf, OV_BEFORE) == NULL);
+                  eassert (buffer_get_overlays (buf, OV_AFTER) == NULL);
 
                   set_buffer_internal (buf);
                   Ferase_buffer ();
diff --git a/src/indent.c b/src/indent.c
index 6b7e79fb7a5..597f05da990 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -337,8 +337,7 @@ current_column (void)
   /* If the buffer has overlays, text properties,
      or multibyte characters, use a more general algorithm.  */
   if (buffer_get_intervals (current_buffer)
-      || current_buffer->overlays_before
-      || current_buffer->overlays_after
+      || buffer_has_overlays ()
       || Z != Z_BYTE)
     return current_column_1 ();
 
diff --git a/src/insdel.c b/src/insdel.c
index ec0d3b31f70..f058ffc2bda 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1993,7 +1993,7 @@ signal_before_change (ptrdiff_t start_int, ptrdiff_t end_int,
       XSETCDR (rvoe_arg, Qt);
     }
 
-  if (current_buffer->overlays_before || current_buffer->overlays_after)
+  if (buffer_has_overlays ())
     {
       PRESERVE_VALUE;
       report_overlay_modification (FETCH_START, FETCH_END, 0,
@@ -2029,8 +2029,7 @@ signal_after_change (ptrdiff_t charpos, ptrdiff_t lendel, ptrdiff_t lenins)
      just record the args that we were going to use.  */
   if (! NILP (Vcombine_after_change_calls)
       && NILP (Vbefore_change_functions)
-      && !current_buffer->overlays_before
-      && !current_buffer->overlays_after)
+      && !buffer_has_overlays ())
     {
       Lisp_Object elt;
 
@@ -2072,7 +2071,7 @@ signal_after_change (ptrdiff_t charpos, ptrdiff_t lendel, ptrdiff_t lenins)
       XSETCDR (rvoe_arg, Qt);
     }
 
-  if (current_buffer->overlays_before || current_buffer->overlays_after)
+  if (buffer_has_overlays ())
     report_overlay_modification (make_number (charpos),
                                  make_number (charpos + lenins),
                                  1,
diff --git a/src/intervals.c b/src/intervals.c
index e9c3929670e..02ffe7ad90d 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -1870,8 +1870,7 @@ set_point_both (ptrdiff_t charpos, ptrdiff_t bytepos)
      whether or not there are intervals in the buffer.  */
   eassert (charpos <= ZV && charpos >= BEGV);
 
-  have_overlays = (current_buffer->overlays_before
-                   || current_buffer->overlays_after);
+  have_overlays = buffer_has_overlays ();
 
   /* If we have no text properties and overlays,
      then we can do it quickly.  */
diff --git a/src/print.c b/src/print.c
index 8c6d1eabc18..718e6a96329 100644
--- a/src/print.c
+++ b/src/print.c
@@ -498,8 +498,8 @@ temp_output_buffer_setup (const char *bufname)
   BVAR (current_buffer, read_only) = Qnil;
   BVAR (current_buffer, filename) = Qnil;
   BVAR (current_buffer, undo_list) = Qt;
-  eassert (current_buffer->overlays_before == NULL);
-  eassert (current_buffer->overlays_after == NULL);
+  eassert (buffer_get_overlays (NULL, OV_BEFORE) == NULL);
+  eassert (buffer_get_overlays (NULL, OV_AFTER) == NULL);
   BVAR (current_buffer, enable_multibyte_characters)
     = BVAR (&buffer_defaults, enable_multibyte_characters);
   specbind (Qinhibit_read_only, Qt);
diff --git a/src/xdisp.c b/src/xdisp.c
index a2fc4f61669..39a6067278f 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -5445,7 +5445,7 @@ load_overlay_strings (struct it *it, ptrdiff_t charpos)
   while (0)
 
   /* Process overlay before the overlay center.  */
-  for (ov = current_buffer->overlays_before; ov; ov = ov->next)
+  for (ov = buffer_get_overlays (NULL, OV_BEFORE); ov; ov = ov->next)
     {
       XSETMISC (overlay, ov);
       eassert (OVERLAYP (overlay));
@@ -5485,7 +5485,7 @@ load_overlay_strings (struct it *it, ptrdiff_t charpos)
     }
 
   /* Process overlays after the overlay center.  */
-  for (ov = current_buffer->overlays_after; ov; ov = ov->next)
+  for (ov = buffer_get_overlays (NULL, OV_AFTER); ov; ov = ov->next)
     {
       XSETMISC (overlay, ov);
       eassert (OVERLAYP (overlay));