* New index_merge EXPLAIN output format

 * Fixed a problem with wrong query results for partially covering keys in ROR-index_merge
 * ROR-intersection retrieval plan choice algorithm now uses less disk IO
   - and properly processes clustered PK range scans 
 * Fixed several minor range optimizer problems
 * Added more comments
 * Code cleanup


mysql-test/r/index_merge.result:
  New index_merge EXPLAIN output format changes
mysql-test/r/index_merge_innodb.result:
  New index_merge EXPLAIN output format changes
mysql-test/r/index_merge_ror.result:
  New index_merge EXPLAIN output format changes
  Added test for scans on keys that cover fields partially
  Fixed a minor ROR optimizer problem
mysql-test/r/index_merge_ror_cpk.result:
  More tests added
mysql-test/t/index_merge_ror.test:
  New index_merge EXPLAIN output format changes
  Added test for scans on keys that cover fields partially
  Fixed a minor ROR optimizer problem
mysql-test/t/index_merge_ror_cpk.test:
  More tests added
mysys/my_bitmap.c:
  Comments added, code cleanup
sql/opt_range.cc:
  Comments added, code cleanup
  Numerous fixes, see changeset description
sql/opt_range.h:
  Comments added, code cleanup
  New index_merge EXPLAIN output format related changes
sql/sql_select.cc:
  Comments added, code cleanup
  New index_merge EXPLAIN output

1 files changed, 16 insertions, 6 deletions

diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index 3c4caa413a9..a6a37fd5441 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -28,6 +28,9 @@
     * when both arguments are bitmaps, they must be of the same size
     * bitmap_intersect() is an exception :)
       (for for Bitmap::intersect(ulonglong map2buff))
+  
+  If THREAD is defined all bitmap operations except bitmap_init/bitmap_free 
+  are thread-safe.
 
   TODO:
   Make assembler THREAD safe versions of these using test-and-set instructions
@@ -332,29 +335,36 @@ void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
 
 
 /*
-  Get number of set bits in the bitmap 
+  SYNOPSIS
+    bitmap_bits_set()
+      map
+  RETURN
+    Number of set bits in the bitmap.
 */
+
 uint bitmap_bits_set(const MY_BITMAP *map)
 {  
-  uchar *m= map->bitmap,
-        *end= map->bitmap+map->bitmap_size;
+  uchar *m= map->bitmap;
+  uchar *end= m + map->bitmap_size;
   uint res= 0;
 
   DBUG_ASSERT(map->bitmap);
-
   bitmap_lock((MY_BITMAP *)map);
   while (m < end)
   {
     res+= my_count_bits_ushort(*m++);
   }
-
   bitmap_unlock((MY_BITMAP *)map);
   return res;
 }
 
 
 /* 
-  Return number of first zero bit or MY_BIT_NONE if all bits are set.
+  SYNOPSIS
+    bitmap_get_first()
+      map
+  RETURN 
+    Number of first unset bit in the bitmap or MY_BIT_NONE if all bits are set.
 */
 
 uint bitmap_get_first(const MY_BITMAP *map)