Fix for BUG33649: Post-review fixes

sql/sql_class.h:
  Fix for BUG33649: Post-review fixes: added RNEXT_SAME
sql/sql_handler.cc:
  Fix for BUG33649: Post-review fixes: added RNEXT_SAME

sql/sql_class.h

@@ -28,7 +28,7 @@ class Load_log_event;
 class Slave_log_event;
 
 enum enum_enable_or_disable { LEAVE_AS_IS, ENABLE, DISABLE };
-enum enum_ha_read_modes { RFIRST, RNEXT, RPREV, RLAST, RKEY };
+enum enum_ha_read_modes { RFIRST, RNEXT, RPREV, RLAST, RKEY, RNEXT_SAME };
 enum enum_duplicates { DUP_ERROR, DUP_REPLACE, DUP_IGNORE };
 enum enum_log_type { LOG_CLOSED, LOG_TO_BE_OPENED, LOG_NORMAL, LOG_NEW, LOG_BIN};
 enum enum_delay_key_write { DELAY_KEY_WRITE_NONE, DELAY_KEY_WRITE_ON,

sql/sql_handler.cc

@@ -103,7 +103,7 @@ int mysql_ha_closeall(THD *thd, TABLE_LIST *tables)
 }
 
 static enum enum_ha_read_modes rkey_to_rnext[]=
-    { RKEY, RNEXT, RPREV, RNEXT, RPREV, RNEXT, RPREV };
+    { RNEXT_SAME, RNEXT, RPREV, RNEXT, RPREV, RNEXT, RPREV };
 
 
 int mysql_ha_read(THD *thd, TABLE_LIST *tables,
@@ -152,9 +152,10 @@ int mysql_ha_read(THD *thd, TABLE_LIST *tables,
   MYSQL_LOCK *lock=mysql_lock_tables(thd,&tables->table,1);
   HANDLER_TABLES_HACK(thd);
   
-  byte *key= NULL;
+  byte *key;
   uint key_len;
-  LINT_INIT(key_len); /* protected by key key variable */
+  LINT_INIT(key); 
+  LINT_INIT(key_len); 
   if (!lock)
      goto err0; // mysql_lock_tables() printed error message already
 
@@ -187,14 +188,12 @@ int mysql_ha_read(THD *thd, TABLE_LIST *tables,
       DBUG_ASSERT(keyname != 0);
       err=table->file->index_prev(table->record[0]);
       break;
-    case RKEY:
-    {
-      if (key)
-      {
+    case RNEXT_SAME:
       /* Continue scan on "(keypart1,keypart2,...)=(c1, c2, ...)  */
+      DBUG_ASSERT(keyname != 0);
       err= table->file->index_next_same(table->record[0], key, key_len);
-      }
-      else
+      break;
+    case RKEY:
     {
       DBUG_ASSERT(keyname != 0);
       KEY *keyinfo=table->key_info+keyno;
@@ -228,7 +227,6 @@ int mysql_ha_read(THD *thd, TABLE_LIST *tables,
       err=table->file->index_read(table->record[0],
                                   key,key_len,ha_rkey_mode);
       mode=rkey_to_rnext[(int)ha_rkey_mode];
-      }
       break;
     }
     default: