Merge with MySQL 5.1.50

- Changed to still use bcmp() in certain cases becasue
  - Faster for short unaligneed strings than memcmp()
  - Bettern when using valgrind
- Changed to use my_sprintf() instead of sprintf() to get higher portability for old systems
- Changed code to use MariaDB version of select->skip_record()
- Removed -%::SCCS/s.% from Makefile.am:s to remove automake warnings

1 files changed, 13 insertions, 5 deletions

diff --git a/sql/handler.h b/sql/handler.h
index d0b5bbba996..36b0bf77b7a 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -93,7 +93,10 @@
 #define HA_PRIMARY_KEY_IN_READ_INDEX (1 << 15)
 /*
   If HA_PRIMARY_KEY_REQUIRED_FOR_POSITION is set, it means that to position()
-  uses a primary key. Without primary key, we can't call position().
+  uses a primary key given by the record argument.
+  Without primary key, we can't call position().
+  If not set, the position is returned as the current rows position
+  regardless of what argument is given.
 */ 
 #define HA_PRIMARY_KEY_REQUIRED_FOR_POSITION (1 << 16) 
 #define HA_CAN_RTREEKEYS       (1 << 17)
@@ -1461,10 +1464,9 @@ public:
   virtual int rnd_next(uchar *buf)=0;
   virtual int rnd_pos(uchar * buf, uchar *pos)=0;
   /**
-    One has to use this method when to find
-    random position by record as the plain
-    position() call doesn't work for some
-    handlers for random position.
+    This function only works for handlers having
+    HA_PRIMARY_KEY_REQUIRED_FOR_POSITION set.
+    It will return the row with the PK given in the record argument.
   */
   virtual int rnd_pos_by_record(uchar *record)
     {
@@ -1486,6 +1488,12 @@ public:
   virtual ha_rows records_in_range(uint inx, key_range *min_key,
                                    key_range *max_key)
     { return (ha_rows) 10; }
+  /*
+    If HA_PRIMARY_KEY_REQUIRED_FOR_POSITION is set, then it sets ref
+    (reference to the row, aka position, with the primary key given in
+    the record).
+    Otherwise it set ref to the current row.
+  */
   virtual void position(const uchar *record)=0;
   virtual int info(uint)=0; // see my_base.h for full description
   virtual void get_dynamic_partition_info(PARTITION_INFO *stat_info,