MDEV-26345 [debug] some tmp changes to fix

storage/spider/mysql-test/spider/bugfix/r/mdev_26345.result

@@ -10,10 +10,10 @@ OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
 create table t2 (a int, b int, PRIMARY KEY (a, b));
 create table t1 (a int, b int, PRIMARY KEY (a, b)) ENGINE=Spider
 COMMENT='WRAPPER "mysql", srv "srv",TABLE "t2"';
-insert into t1 VALUES (1,1), (1,2), (2,11);
+insert into t1 VALUES (1,4), (1,2), (2,11);
 SELECT MIN(b), a FROM t1 WHERE a=1;
 MIN(b)	a
-1	1
+2	1
 SELECT MAX(b), a FROM t1 WHERE a<3;
 MAX(b)	a
 11	1

storage/spider/mysql-test/spider/bugfix/t/mdev_26345.test

@@ -18,7 +18,7 @@ create table t2 (a int, b int, PRIMARY KEY (a, b));
 create table t1 (a int, b int, PRIMARY KEY (a, b)) ENGINE=Spider
 COMMENT='WRAPPER "mysql", srv "srv",TABLE "t2"';
 
-insert into t1 VALUES (1,1), (1,2), (2,11);
+insert into t1 VALUES (1,4), (1,2), (2,11);
 SELECT MIN(b), a FROM t1 WHERE a=1;
 SELECT MAX(b), a FROM t1 WHERE a<3;
 

storage/spider/spd_db_include.h

@@ -1764,6 +1764,7 @@ typedef struct st_spider_result_list
   volatile
 #endif
     SPIDER_RESULT         *current;
+  MY_BITMAP               skip;
   KEY                     *key_info;
   int                     key_order;
   spider_string           *sqls;

storage/spider/spd_db_mysql.cc

@@ -342,6 +342,15 @@ SPIDER_DBTON spider_dbton_mariadb = {
   SPIDER_MATURITY_STABLE
 };
 
+void spider_db_mbase_row::skip(MY_BITMAP *map)
+{
+  for (uint i= 0, j= 0; j < field_count; j++)
+  {
+    if (!bitmap_is_set(map, j))
+      row[i++]= row[j];
+  }
+}
+
 spider_db_mbase_row::spider_db_mbase_row(
   uint dbton_id
 ) : spider_db_row(dbton_id),
@@ -13975,8 +13984,15 @@ int spider_mbase_handler::append_list_item_select(
   DBUG_ENTER("spider_mbase_handler::append_list_item_select");
   DBUG_PRINT("info",("spider this=%p", this));
   begin = str->length();
+  uint i= -1;
   while ((item = it++))
   {
+    i++;
+    if (item->const_item())
+    {
+      bitmap_set_bit(&spider->result_list.skip, i);
+      continue;
+    }
     if (skip > 0)
     {
       str->reserve(2);