Invalidate region caches only if buffer text is going to be changed.

* lisp.h (modify_region_1): Remove 3rd arg and rename to...
(modify_text): ...new prototype.
(prepare_to_modify_buffer_1): New prototype.
* textprop.c (modify_region): Rename to...
(modify_text_properties): ...new function.
(add_text_properties_1, set_text_properties, Fremove_text_properties)
(Fremove_list_of_text_properties): Adjust users.
* insdel.c (modify_region_1): Remove 3rd arg and reimplement as...
(modify_text): ...new function.
(prepare_to_modify_buffer): Reimplement mostly as a wrapper for...
(prepare_to_modify_buffer_1): ...new function.
* casefiddle.c (casify_region):
* editfns.c (Fsubst_char_in_region, Ftranslate_region_internal)
(Ftranspose_regions): Use modify_text.

6 files changed, 72 insertions, 38 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 35b5c1cfe5c..7b7d9b56cb5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,21 @@
+2013-08-06  Dmitry Antipov  <dmantipov@yandex.ru>
+
+	Invalidate region caches only if buffer text is going to be changed.
+	* lisp.h (modify_region_1): Remove 3rd arg and rename to...
+	(modify_text): ...new prototype.
+	(prepare_to_modify_buffer_1): New prototype.
+	* textprop.c (modify_region): Rename to...
+	(modify_text_properties): ...new function.
+	(add_text_properties_1, set_text_properties, Fremove_text_properties)
+	(Fremove_list_of_text_properties): Adjust users.
+	* insdel.c (modify_region_1): Remove 3rd arg and reimplement as...
+	(modify_text): ...new function.
+	(prepare_to_modify_buffer): Reimplement mostly as a wrapper for...
+	(prepare_to_modify_buffer_1): ...new function.
+	* casefiddle.c (casify_region):
+	* editfns.c (Fsubst_char_in_region, Ftranslate_region_internal)
+	(Ftranspose_regions): Use modify_text.
+
 2013-08-05  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* lisp.mk (lisp): Add nadvice.elc.
diff --git a/src/casefiddle.c b/src/casefiddle.c
index 7f5b99752fa..5a40790f87f 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -214,7 +214,7 @@ casify_region (enum case_action flag, Lisp_Object b, Lisp_Object e)
   validate_region (&b, &e);
   start = XFASTINT (b);
   end = XFASTINT (e);
-  modify_region_1 (start, end, false);
+  modify_text (start, end);
   record_change (start, end - start);
   start_byte = CHAR_TO_BYTE (start);
 
diff --git a/src/editfns.c b/src/editfns.c
index 50bde90788d..90346a88eb2 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -2928,7 +2928,7 @@ Both characters must have the same length of multi-byte form.  */)
 	  else if (!changed)
 	    {
 	      changed = -1;
-	      modify_region_1 (pos, XINT (end), false);
+	      modify_text (pos, XINT (end));
 
 	      if (! NILP (noundo))
 		{
@@ -3104,7 +3104,7 @@ It returns the number of characters changed.  */)
   pos = XINT (start);
   pos_byte = CHAR_TO_BYTE (pos);
   end_pos = XINT (end);
-  modify_region_1 (pos, end_pos, false);
+  modify_text (pos, end_pos);
 
   cnt = 0;
   for (; pos < end_pos; )
@@ -4615,7 +4615,7 @@ Transposing beyond buffer boundaries is an error.  */)
 
   if (end1 == start2)		/* adjacent regions */
     {
-      modify_region_1 (start1, end2, false);
+      modify_text (start1, end2);
       record_change (start1, len1 + len2);
 
       tmp_interval1 = copy_intervals (cur_intv, start1, len1);
@@ -4674,8 +4674,8 @@ Transposing beyond buffer boundaries is an error.  */)
         {
 	  USE_SAFE_ALLOCA;
 
-          modify_region_1 (start1, end1, false);
-          modify_region_1 (start2, end2, false);
+          modify_text (start1, end1);
+          modify_text (start2, end2);
           record_change (start1, len1);
           record_change (start2, len2);
           tmp_interval1 = copy_intervals (cur_intv, start1, len1);
@@ -4708,7 +4708,7 @@ Transposing beyond buffer boundaries is an error.  */)
         {
 	  USE_SAFE_ALLOCA;
 
-          modify_region_1 (start1, end2, false);
+          modify_text (start1, end2);
           record_change (start1, (end2 - start1));
           tmp_interval1 = copy_intervals (cur_intv, start1, len1);
           tmp_interval_mid = copy_intervals (cur_intv, end1, len_mid);
@@ -4741,7 +4741,7 @@ Transposing beyond buffer boundaries is an error.  */)
 	  USE_SAFE_ALLOCA;
 
           record_change (start1, (end2 - start1));
-          modify_region_1 (start1, end2, false);
+          modify_text (start1, end2);
 
           tmp_interval1 = copy_intervals (cur_intv, start1, len1);
           tmp_interval_mid = copy_intervals (cur_intv, end1, len_mid);
diff --git a/src/insdel.c b/src/insdel.c
index 58c3e15c233..ac64299a997 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1756,27 +1756,22 @@ del_range_2 (ptrdiff_t from, ptrdiff_t from_byte,
   return deletion;
 }
 
-/* Call this if you're about to change the region of current buffer
+/* Call this if you're about to change the text of current buffer
    from character positions START to END.  This checks the read-only
    properties of the region, calls the necessary modification hooks,
    and warns the next redisplay that it should pay attention to that
-   area.
-
-   If PRESERVE_CHARS_MODIFF, do not update CHARS_MODIFF.
-   Otherwise set CHARS_MODIFF to the new value of MODIFF.  */
+   area.  */
 
 void
-modify_region_1 (ptrdiff_t start, ptrdiff_t end, bool preserve_chars_modiff)
+modify_text (ptrdiff_t start, ptrdiff_t end)
 {
   prepare_to_modify_buffer (start, end, NULL);
 
   BUF_COMPUTE_UNCHANGED (current_buffer, start - 1, end);
-
   if (MODIFF <= SAVE_MODIFF)
     record_first_change ();
   MODIFF++;
-  if (! preserve_chars_modiff)
-    CHARS_MODIFF = MODIFF;
+  CHARS_MODIFF = MODIFF;
 
   bset_point_before_scroll (current_buffer, Qnil);
 }
@@ -1792,8 +1787,8 @@ modify_region_1 (ptrdiff_t start, ptrdiff_t end, bool preserve_chars_modiff)
    by holding its value temporarily in a marker.  */
 
 void
-prepare_to_modify_buffer (ptrdiff_t start, ptrdiff_t end,
-			  ptrdiff_t *preserve_ptr)
+prepare_to_modify_buffer_1 (ptrdiff_t start, ptrdiff_t end,
+			    ptrdiff_t *preserve_ptr)
 {
   struct buffer *base_buffer;
 
@@ -1864,6 +1859,17 @@ prepare_to_modify_buffer (ptrdiff_t start, ptrdiff_t end,
     }
 
   signal_before_change (start, end, preserve_ptr);
+  Vdeactivate_mark = Qt;
+}
+
+/* Like above, but called when we know that the buffer text
+   will be modified and region caches should be invalidated.  */
+
+void
+prepare_to_modify_buffer (ptrdiff_t start, ptrdiff_t end,
+			  ptrdiff_t *preserve_ptr)
+{
+  prepare_to_modify_buffer_1 (start, end, preserve_ptr);
 
   if (current_buffer->newline_cache)
     invalidate_region_cache (current_buffer,
@@ -1873,10 +1879,8 @@ prepare_to_modify_buffer (ptrdiff_t start, ptrdiff_t end,
     invalidate_region_cache (current_buffer,
                              current_buffer->width_run_cache,
                              start - BEG, Z - end);
-
-  Vdeactivate_mark = Qt;
 }
-
+
 /* These macros work with an argument named `preserve_ptr'
    and a local variable named `preserve_marker'.  */
 
diff --git a/src/lisp.h b/src/lisp.h
index 085acb54348..8ca6d05a821 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3370,8 +3370,9 @@ extern void del_range_byte (ptrdiff_t, ptrdiff_t, bool);
 extern void del_range_both (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t, bool);
 extern Lisp_Object del_range_2 (ptrdiff_t, ptrdiff_t,
 				ptrdiff_t, ptrdiff_t, bool);
-extern void modify_region_1 (ptrdiff_t, ptrdiff_t, bool);
+extern void modify_text (ptrdiff_t, ptrdiff_t);
 extern void prepare_to_modify_buffer (ptrdiff_t, ptrdiff_t, ptrdiff_t *);
+extern void prepare_to_modify_buffer_1 (ptrdiff_t, ptrdiff_t, ptrdiff_t *);
 extern void signal_after_change (ptrdiff_t, ptrdiff_t, ptrdiff_t);
 extern void adjust_after_insert (ptrdiff_t, ptrdiff_t, ptrdiff_t,
 				 ptrdiff_t, ptrdiff_t);
diff --git a/src/textprop.c b/src/textprop.c
index 282ae11d4ac..b804f345047 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -93,15 +93,25 @@ text_read_only (Lisp_Object propval)
   xsignal0 (Qtext_read_only);
 }
 
-/* Prepare to modify the region of BUFFER from START to END.  */
+/* Prepare to modify the text properties of BUFFER from START to END.  */
 
 static void
-modify_region (Lisp_Object buffer, Lisp_Object start, Lisp_Object end)
+modify_text_properties (Lisp_Object buffer, Lisp_Object start, Lisp_Object end)
 {
+  ptrdiff_t b = XINT (start), e = XINT (end);
   struct buffer *buf = XBUFFER (buffer), *old = current_buffer;
 
   set_buffer_internal (buf);
-  modify_region_1 (XINT (start), XINT (end), true);
+
+  prepare_to_modify_buffer_1 (b, e, NULL);
+
+  BUF_COMPUTE_UNCHANGED (buf, b - 1, e);
+  if (MODIFF <= SAVE_MODIFF)
+    record_first_change ();
+  MODIFF++;
+
+  bset_point_before_scroll (current_buffer, Qnil);
+
   set_buffer_internal (old);
 }
 
@@ -1213,9 +1223,9 @@ add_text_properties_1 (Lisp_Object start, Lisp_Object end,
       ptrdiff_t prev_total_length = TOTAL_LENGTH (i);
       ptrdiff_t prev_pos = i->position;
 
-      modify_region (object, start, end);
+      modify_text_properties (object, start, end);
       /* If someone called us recursively as a side effect of
-	 modify_region, and changed the intervals behind our back
+	 modify_text_properties, and changed the intervals behind our back
 	 (could happen if lock_file, called by prepare_to_modify_buffer,
 	 triggers redisplay, and that calls add-text-properties again
 	 in the same buffer), we cannot continue with I, because its
@@ -1357,7 +1367,8 @@ into it.  */)
    otherwise.  */
 
 Lisp_Object
-set_text_properties (Lisp_Object start, Lisp_Object end, Lisp_Object properties, Lisp_Object object, Lisp_Object coherent_change_p)
+set_text_properties (Lisp_Object start, Lisp_Object end, Lisp_Object properties,
+		     Lisp_Object object, Lisp_Object coherent_change_p)
 {
   register INTERVAL i;
   Lisp_Object ostart, oend;
@@ -1403,7 +1414,7 @@ set_text_properties (Lisp_Object start, Lisp_Object end, Lisp_Object properties,
     }
 
   if (BUFFERP (object) && !NILP (coherent_change_p))
-    modify_region (object, start, end);
+    modify_text_properties (object, start, end);
 
   set_text_properties_1 (start, end, properties, object, i);
 
@@ -1558,9 +1569,9 @@ Use `set-text-properties' if you want to remove all text properties.  */)
       ptrdiff_t prev_total_length = TOTAL_LENGTH (i);
       ptrdiff_t prev_pos = i->position;
 
-      modify_region (object, start, end);
+      modify_text_properties (object, start, end);
       /* If someone called us recursively as a side effect of
-	 modify_region, and changed the intervals behind our back
+	 modify_text_properties, and changed the intervals behind our back
 	 (could happen if lock_file, called by prepare_to_modify_buffer,
 	 triggers redisplay, and that calls add-text-properties again
 	 in the same buffer), we cannot continue with I, because its
@@ -1667,9 +1678,9 @@ Return t if any property was actually removed, nil otherwise.  */)
 
   /* We are at the beginning of an interval, with len to scan.
      The flag `modified' records if changes have been made.
-     When object is a buffer, we must call modify_region before changes are
-     made and signal_after_change when we are done.
-     We call modify_region before calling remove_properties if modified == 0,
+     When object is a buffer, we must call modify_text_properties
+     before changes are made and signal_after_change when we are done.
+     We call modify_text_properties before calling remove_properties if modified == 0,
      and we call signal_after_change before returning if modified != 0. */
   for (;;)
     {
@@ -1693,7 +1704,7 @@ Return t if any property was actually removed, nil otherwise.  */)
 	  else if (LENGTH (i) == len)
 	    {
 	      if (!modified && BUFFERP (object))
-		modify_region (object, start, end);
+		modify_text_properties (object, start, end);
 	      remove_properties (Qnil, properties, i, object);
 	      if (BUFFERP (object))
 		signal_after_change (XINT (start), XINT (end) - XINT (start),
@@ -1706,7 +1717,7 @@ Return t if any property was actually removed, nil otherwise.  */)
 	      i = split_interval_left (i, len);
 	      copy_properties (unchanged, i);
 	      if (!modified && BUFFERP (object))
-		modify_region (object, start, end);
+		modify_text_properties (object, start, end);
 	      remove_properties (Qnil, properties, i, object);
 	      if (BUFFERP (object))
 		signal_after_change (XINT (start), XINT (end) - XINT (start),
@@ -1717,7 +1728,7 @@ Return t if any property was actually removed, nil otherwise.  */)
       if (interval_has_some_properties_list (properties, i))
 	{
 	  if (!modified && BUFFERP (object))
-	    modify_region (object, start, end);
+	    modify_text_properties (object, start, end);
 	  remove_properties (Qnil, properties, i, object);
 	  modified = 1;
 	}