2 files changed, 20 insertions, 9 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c41202bcfee..eebb10fb472 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,10 +1,17 @@
-2012-02-01  Kenichi Handa  <handa@m17n.org>
+2012-02-02  Kenichi Handa  <handa@m17n.org>
 
         * xdisp.c (BUILD_COMPOSITE_GLYPH_STRING): Initialize first_s to
         NULL (Bug#6988).
         (x_produce_glyphs): If the component of a composition is a null
         string, set it->pixel_width to 1 to avoid zero-width glyph.
 
+2012-02-01  Eli Zaretskii  <eliz@gnu.org>
+
+        * ralloc.c (resize_bloc, r_alloc_sbrk): Don't call memmove if its
+        first 2 arguments are identical.  This makes inserting large
+        output from a subprocess an order of magnitude faster on
+        MS-Windows, where all sbrk'ed memory is always contiguous.
+
 2012-01-31  Glenn Morris  <rgm@gnu.org>
 
         * nsterm.m (syms_of_nsterm) <x-toolkit-scroll-bars>:
@@ -21,7 +28,6 @@
 
 2012-01-28  Chong Yidong  <cyd@gnu.org>
 
-
         * minibuf.c (syms_of_minibuf): Doc fix (Bug#10550).
 
 2012-01-26  Chong Yidong  <cyd@gnu.org>
@@ -2376,7 +2382,7 @@
         Remove unreachable code.
         (read_hex, load_charset_map_from_file): Check for integer overflow.
 
-        * xterm.c: don't go over XClientMessageEvent limit
+        * xterm.c: Don't go over XClientMessageEvent limit.
         (scroll_bar_windows_size): Now ptrdiff_t, as we prefer signed.
         (x_send_scroll_bar_event): Likewise.  Check that the size does not
         exceed limits imposed by XClientMessageEvent, as well as the usual
@@ -5667,7 +5673,7 @@
 
         * ccl.c (ccl_driver): Redo slightly to avoid the need for 'unsigned'.
 
-        ccl: add integer overflow checks
+        ccl: Add integer overflow checks.
         * ccl.c (CCL_CODE_MAX, GET_CCL_RANGE, GET_CCL_CODE, GET_CCL_INT):
         (IN_INT_RANGE): New macros.
         (ccl_driver): Use them to check for integer overflow when
diff --git a/src/ralloc.c b/src/ralloc.c
index 13587b9ffd4..896ad9f3155 100644
--- a/src/ralloc.c
+++ b/src/ralloc.c
@@ -636,7 +636,8 @@ resize_bloc (bloc_ptr bloc, SIZE size)
             }
           else
             {
-              memmove (b->new_data, b->data, b->size);
+              if (b->new_data != b->data)
+                memmove (b->new_data, b->data, b->size);
               *b->variable = b->data = b->new_data;
             }
         }
@@ -647,7 +648,8 @@ resize_bloc (bloc_ptr bloc, SIZE size)
         }
       else
         {
-          memmove (bloc->new_data, bloc->data, old_size);
+          if (bloc->new_data != bloc->data)
+            memmove (bloc->new_data, bloc->data, old_size);
           memset ((char *) bloc->new_data + old_size, 0, size - old_size);
           *bloc->variable = bloc->data = bloc->new_data;
         }
@@ -663,7 +665,8 @@ resize_bloc (bloc_ptr bloc, SIZE size)
             }
           else
             {
-              memmove (b->new_data, b->data, b->size);
+              if (b->new_data != b->data)
+                memmove (b->new_data, b->data, b->size);
               *b->variable = b->data = b->new_data;
             }
         }
@@ -816,7 +819,8 @@ r_alloc_sbrk (long int size)
              header.  */
           for (b = last_bloc; b != NIL_BLOC; b = b->prev)
             {
-              memmove (b->new_data, b->data, b->size);
+              if (b->new_data != b->data)
+                memmove (b->new_data, b->data, b->size);
               *b->variable = b->data = b->new_data;
             }
 
@@ -862,7 +866,8 @@ r_alloc_sbrk (long int size)
 
           for (b = first_bloc; b != NIL_BLOC; b = b->next)
             {
-              memmove (b->new_data, b->data, b->size);
+              if (b->new_data != b->data)
+                memmove (b->new_data, b->data, b->size);
               *b->variable = b->data = b->new_data;
             }
         }