1 files changed, 86 insertions, 148 deletions

diff --git a/src/buffer.c b/src/buffer.c
index c5a58429ef3..129fee7c095 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1954,6 +1954,24 @@ struct sortstr
   int priority;
 };
 
+struct sortstrlist
+{
+  struct sortstr *buf;  /* An array that expands as needed; never freed.  */
+  int size;             /* Allocated length of that array.  */
+  int used;             /* How much of the array is currently in use.  */
+  int bytes;            /* Total length of the strings in buf.  */
+};
+
+/* Buffers for storing information about the overlays touching a given
+   position.  These could be automatic variables in overlay_strings, but
+   it's more efficient to hold onto the memory instead of repeatedly
+   allocating and freeing it.  */
+static struct sortstrlist overlay_heads, overlay_tails;
+static char *overlay_str_buf;
+
+/* Allocated length of overlay_str_buf.  */
+static int overlay_str_len;
+
 /* A comparison function suitable for passing to qsort.  */
 static int
 cmp_for_strings (as1, as2)
@@ -1968,13 +1986,28 @@ cmp_for_strings (as1, as2)
   return 0;
 }
 
-/* Buffers for storing the overlays touching a given position.
-   These are expanded as needed, but never freed.  */
-static struct sortstr *overlay_heads, *overlay_tails;
-static char *overlay_str_buf;
-
-/* Allocated length of those buffers.  */
-static int overlay_heads_len, overlay_tails_len, overlay_str_len;
+static void
+record_overlay_string (ssl, str, pri, size)
+     struct sortstrlist *ssl;
+     Lisp_Object str;
+     Lisp_Object pri;
+     int size;
+{
+  if (ssl->used == ssl->size)
+    {
+      if (ssl->buf)
+        ssl->size *= 2;
+      else
+        ssl->size = 5;
+      ssl->buf = ((struct sortstr *)
+                  xrealloc (ssl->buf, ssl->size * sizeof (struct sortstr)));
+    }
+  ssl->buf[ssl->used].string = str;
+  ssl->buf[ssl->used].size = size;
+  ssl->buf[ssl->used].priority = (INTEGERP (pri) ? XINT (pri) : 0);
+  ssl->used++;
+  ssl->bytes += XSTRING (str)->size;
+}
 
 /* Return the concatenation of the strings associated with overlays that
    begin or end at POS, ignoring overlays that are specific to a window
@@ -1989,11 +2022,11 @@ overlay_strings (pos, w, pstr)
      struct window *w;
      char **pstr;
 {
-  Lisp_Object ov, overlay, window, str, tem;
-  int ntail = 0, nhead = 0;
-  int total = 0;
+  Lisp_Object ov, overlay, window, str;
   int startpos, endpos;
 
+  overlay_heads.used = overlay_heads.bytes = 0;
+  overlay_tails.used = overlay_tails.bytes = 0;
   for (ov = current_buffer->overlays_before; CONSP (ov); ov = XCONS (ov)->cdr)
     {
       overlay = XCONS (ov)->car;
@@ -2009,66 +2042,16 @@ overlay_strings (pos, w, pstr)
       window = Foverlay_get (overlay, Qwindow);
       if (WINDOWP (window) && XWINDOW (window) != w)
         continue;
-      if (endpos == pos)
-        {
-          str = Foverlay_get (overlay, Qafter_string);
-          if (STRINGP (str))
-            {
-              if (ntail == overlay_tails_len)
-                {
-                  if (! overlay_tails)
-                    {
-                      overlay_tails_len = 5;
-                      overlay_tails = ((struct sortstr *)
-                                       xmalloc (5 * sizeof (struct sortstr)));
-                    }
-                  else
-                    {
-                      overlay_tails_len *= 2;
-                      overlay_tails = ((struct sortstr *)
-                                       xrealloc (overlay_tails,
-                                                 (overlay_tails_len
-                                                  * sizeof (struct sortstr))));
-                    }
-                }
-              overlay_tails[ntail].string = str;
-              overlay_tails[ntail].size = endpos - startpos;
-              tem = Foverlay_get (overlay, Qpriority);
-              overlay_tails[ntail].priority = (INTEGERP (tem) ? XINT (tem) : 0);
-              ntail++;
-              total += XSTRING (str)->size;
-            }
-        }
-      if (startpos == pos)
-        {
-          str = Foverlay_get (overlay, Qbefore_string);
-          if (STRINGP (str))
-            {
-              if (nhead == overlay_heads_len)
-                {
-                  if (! overlay_heads)
-                    {
-                      overlay_heads_len = 5;
-                      overlay_heads = ((struct sortstr *)
-                                       xmalloc (5 * sizeof (struct sortstr)));
-                    }
-                  else
-                    {
-                      overlay_heads_len *= 2;
-                      overlay_heads = ((struct sortstr *)
-                                       xrealloc (overlay_heads,
-                                                 (overlay_heads_len
-                                                  * sizeof (struct sortstr))));
-                    }
-                }
-              overlay_heads[nhead].string = str;
-              overlay_heads[nhead].size = endpos - startpos;
-              tem = Foverlay_get (overlay, Qpriority);
-              overlay_heads[nhead].priority = (INTEGERP (tem) ? XINT (tem) : 0);
-              nhead++;
-              total += XSTRING (str)->size;
-            }
-        }
+      if (endpos == pos
+          && (str = Foverlay_get (overlay, Qafter_string), STRINGP (str)))
+        record_overlay_string (&overlay_tails, str,
+                               Foverlay_get (overlay, Qpriority),
+                               endpos - startpos);
+      if (startpos == pos
+          && (str = Foverlay_get (overlay, Qbefore_string), STRINGP (str)))
+        record_overlay_string (&overlay_heads, str,
+                               Foverlay_get (overlay, Qpriority),
+                               endpos - startpos);
     }
   for (ov = current_buffer->overlays_after; CONSP (ov); ov = XCONS (ov)->cdr)
     {
@@ -2080,101 +2063,56 @@ overlay_strings (pos, w, pstr)
       endpos = OVERLAY_POSITION (OVERLAY_END (overlay));
       if (startpos > pos)
         break;
-      if (endpos == pos)
-        {
-          str = Foverlay_get (overlay, Qafter_string);
-          if (STRINGP (str))
-            {
-              if (ntail == overlay_tails_len)
-                {
-                  if (! overlay_tails)
-                    {
-                      overlay_tails_len = 5;
-                      overlay_tails = ((struct sortstr *)
-                                       xmalloc (5 * sizeof (struct sortstr)));
-                    }
-                  else
-                    {
-                      overlay_tails_len *= 2;
-                      overlay_tails = ((struct sortstr *)
-                                       xrealloc (overlay_tails,
-                                                 (overlay_tails_len
-                                                  * sizeof (struct sortstr))));
-                    }
-                }
-              overlay_tails[ntail].string = str;
-              overlay_tails[ntail].size = endpos - startpos;
-              tem = Foverlay_get (overlay, Qpriority);
-              overlay_tails[ntail].priority = (INTEGERP (tem) ? XINT (tem) : 0);
-              ntail++;
-              total += XSTRING (str)->size;
-            }
-        }
-      if (startpos == pos)
-        {
-          str = Foverlay_get (overlay, Qbefore_string);
-          if (STRINGP (str))
-            {
-              if (nhead == overlay_heads_len)
-                {
-                  if (! overlay_heads)
-                    {
-                      overlay_heads_len = 5;
-                      overlay_heads = ((struct sortstr *)
-                                       xmalloc (5 * sizeof (struct sortstr)));
-                    }
-                  else
-                    {
-                      overlay_heads_len *= 2;
-                      overlay_heads = ((struct sortstr *)
-                                       xrealloc (overlay_heads,
-                                                 (overlay_heads_len
-                                                  * sizeof (struct sortstr))));
-                    }
-                }
-              overlay_heads[nhead].string = str;
-              overlay_heads[nhead].size = endpos - startpos;
-              tem = Foverlay_get (overlay, Qpriority);
-              overlay_heads[nhead].priority = (INTEGERP (tem) ? XINT (tem) : 0);
-              nhead++;
-              total += XSTRING (str)->size;
-            }
-        }
-    }
-  if (ntail > 1)
-    qsort (overlay_tails, ntail, sizeof (struct sortstr), cmp_for_strings);
-  if (nhead > 1)
-    qsort (overlay_heads, nhead, sizeof (struct sortstr), cmp_for_strings);
-  if (total)
+      if (endpos != pos && startpos != pos)
+        continue;
+      window = Foverlay_get (overlay, Qwindow);
+      if (WINDOWP (window) && XWINDOW (window) != w)
+        continue;
+      if (endpos == pos
+          && (str = Foverlay_get (overlay, Qafter_string), STRINGP (str)))
+        record_overlay_string (&overlay_tails, str,
+                               Foverlay_get (overlay, Qpriority),
+                               endpos - startpos);
+      if (startpos == pos
+          && (str = Foverlay_get (overlay, Qbefore_string), STRINGP (str)))
+        record_overlay_string (&overlay_heads, str,
+                               Foverlay_get (overlay, Qpriority),
+                               endpos - startpos);
+    }
+  if (overlay_tails.used > 1)
+    qsort (overlay_tails.buf, overlay_tails.used, sizeof (struct sortstr),
+           cmp_for_strings);
+  if (overlay_heads.used > 1)
+    qsort (overlay_heads.buf, overlay_heads.used, sizeof (struct sortstr),
+           cmp_for_strings);
+  if (overlay_heads.bytes || overlay_tails.bytes)
     {
+      Lisp_Object tem;
       int i;
       char *p;
+      int total = overlay_heads.bytes + overlay_tails.bytes;
 
       if (total > overlay_str_len)
-        {
-          if (! overlay_str_buf)
-            overlay_str_buf = (char *)xmalloc (total);
-          else
-            overlay_str_buf = (char *)xrealloc (overlay_str_buf, total);
-          overlay_str_len = total;
-        }
+        overlay_str_buf = (char *)xrealloc (overlay_str_buf,
+                                            overlay_str_len = total);
       p = overlay_str_buf;
-      for (i = ntail; --i >= 0;)
+      for (i = overlay_tails.used; --i >= 0;)
         {
-          tem = overlay_tails[i].string;
+          tem = overlay_tails.buf[i].string;
           bcopy (XSTRING (tem)->data, p, XSTRING (tem)->size);
           p += XSTRING (tem)->size;
         }
-      for (i = 0; i < nhead; ++i)
+      for (i = 0; i < overlay_heads.used; ++i)
         {
-          tem = overlay_heads[i].string;
+          tem = overlay_heads.buf[i].string;
           bcopy (XSTRING (tem)->data, p, XSTRING (tem)->size);
           p += XSTRING (tem)->size;
         }
       if (pstr)
         *pstr = overlay_str_buf;
+      return total;
     }
-  return total;
+  return 0;
 }
 
 /* Shift overlays in BUF's overlay lists, to center the lists at POS.  */