MDEV-31524 Fixing spider table param / variable overriding

The existing (incorrect) overriding mechanism is:

Non-minus-one var value overrides table param overrides default value.

Before MDEV-27169, unspecified var value is -1. So if the user sets
both the var to be a value other than -1 and the table param, the var
value will prevail, which is incorrect.

After MDEV-27169, unspecified var value is default value. So if the
user does not set the var but sets the table param, the default value
will prevail, which is even more incorrect.

This patch fixes it so that table param, if specified, always
overrides var value, and the latter if not specified or set to -1,
falls back to the default value

We achieve this by replacing all such overriding in spd_param.cc with
macros that override in the correct way, and removing all the
"overriding -1" lines involving table params in
spider_set_connect_info_default() except for those table params not
defined as sysvar/thdvar in spd_params.cc

We also introduced macros for non-overriding sysvar and thdvar, so
that the code is cleaner and less error-prone

In server versions where MDEV-27169 has not been applied, we also
backport the patch, that is, replacing -1 default values with real
default values

In server versions where MDEV-28006 has not been applied, we do the
same for udf params

storage/spider/mysql-test/spider/bugfix/r/mdev_31524.result

@@ -0,0 +1,46 @@
+
+MDEV-31524 Spider variables that double as table params overriding mechanism is buggy
+
+for master_1
+for child2
+for child3
+SET @old_spider_read_only_mode = @@session.spider_read_only_mode;
+CREATE SERVER $srv FOREIGN DATA WRAPPER MYSQL OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+set session spider_read_only_mode = default;
+create table t2 (c int);
+create table t1 (c int) ENGINE=Spider COMMENT='WRAPPER "mysql", srv "srv_mdev_31524",TABLE "t2"';
+/* 1 */ insert into t1 values (42);
+drop table t1, t2;
+set session spider_read_only_mode = 1;
+create table t2 (c int);
+create table t1 (c int) ENGINE=Spider COMMENT='WRAPPER "mysql", srv "srv_mdev_31524",TABLE "t2"';
+/* 2 */ insert into t1 values (42);
+ERROR HY000: Table 'test.t1' is read only
+drop table t1, t2;
+set session spider_read_only_mode = -1;
+create table t2 (c int);
+create table t1 (c int) ENGINE=Spider COMMENT='WRAPPER "mysql", srv "srv_mdev_31524",TABLE "t2"';
+/* 3 */ insert into t1 values (42);
+drop table t1, t2;
+SET session spider_read_only_mode = default;
+create table t2 (c int);
+create table t1 (c int) ENGINE=Spider COMMENT='read_only_mode "1", WRAPPER "mysql", srv "srv_mdev_31524",TABLE "t2"';
+/* 4 */ insert into t1 values (42);
+ERROR HY000: Table 'test.t1' is read only
+drop table t1, t2;
+set session spider_read_only_mode = 1;
+create table t2 (c int);
+create table t1 (c int) ENGINE=Spider COMMENT='read_only_mode "0", WRAPPER "mysql", srv "srv_mdev_31524",TABLE "t2"';
+/* 5 */ insert into t1 values (42);
+drop table t1, t2;
+SET session spider_read_only_mode = -1;
+create table t2 (c int);
+create table t1 (c int) ENGINE=Spider COMMENT='read_only_mode "1", WRAPPER "mysql", srv "srv_mdev_31524",TABLE "t2"';
+/* 6 */ insert into t1 values (42);
+ERROR HY000: Table 'test.t1' is read only
+drop table t1, t2;
+drop server srv_mdev_31524;
+SET session spider_read_only_mode = @old_spider_read_only_mode;
+for master_1
+for child2
+for child3

storage/spider/mysql-test/spider/bugfix/t/mdev_31524.test

@@ -0,0 +1,73 @@
+--echo
+--echo MDEV-31524 Spider variables that double as table params overriding mechanism is buggy
+--echo
+
+--disable_query_log
+--disable_result_log
+--source ../../t/test_init.inc
+--enable_result_log
+--enable_query_log
+
+--let $srv=srv_mdev_31524
+SET @old_spider_read_only_mode = @@session.spider_read_only_mode;
+evalp CREATE SERVER $srv FOREIGN DATA WRAPPER MYSQL OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+
+# when the user does not set var nor the table option, the default
+# value (0 in this case) takes effect.
+set session spider_read_only_mode = default;
+create table t2 (c int);
+eval create table t1 (c int) ENGINE=Spider COMMENT='WRAPPER "mysql", srv "$srv",TABLE "t2"';
+/* 1 */ insert into t1 values (42);
+drop table t1, t2;
+
+# when the user sets var but not the table option, the var should be
+# take effect.
+set session spider_read_only_mode = 1;
+create table t2 (c int);
+eval create table t1 (c int) ENGINE=Spider COMMENT='WRAPPER "mysql", srv "$srv",TABLE "t2"';
+--error 12518
+/* 2 */ insert into t1 values (42);
+drop table t1, t2;
+
+# when the user sets var to -1 and does not set the table option, the
+# default value takes effect.
+set session spider_read_only_mode = -1;
+create table t2 (c int);
+eval create table t1 (c int) ENGINE=Spider COMMENT='WRAPPER "mysql", srv "$srv",TABLE "t2"';
+/* 3 */ insert into t1 values (42);
+drop table t1, t2;
+
+# when the user does not set the var, but sets the table option, the
+# table option should take effect
+SET session spider_read_only_mode = default;
+create table t2 (c int);
+eval create table t1 (c int) ENGINE=Spider COMMENT='read_only_mode "1", WRAPPER "mysql", srv "$srv",TABLE "t2"';
+--error 12518
+/* 4 */ insert into t1 values (42);
+drop table t1, t2;
+
+# when the user sets both var and table option, the table option
+# should take precedence
+set session spider_read_only_mode = 1;
+create table t2 (c int);
+eval create table t1 (c int) ENGINE=Spider COMMENT='read_only_mode "0", WRAPPER "mysql", srv "$srv",TABLE "t2"';
+/* 5 */ insert into t1 values (42);
+drop table t1, t2;
+
+# when the user sets the var to -1 and sets the table option, the
+# table option should take effect
+SET session spider_read_only_mode = -1;
+create table t2 (c int);
+eval create table t1 (c int) ENGINE=Spider COMMENT='read_only_mode "1", WRAPPER "mysql", srv "$srv",TABLE "t2"';
+--error 12518
+/* 6 */ insert into t1 values (42);
+drop table t1, t2;
+
+eval drop server $srv;
+
+SET session spider_read_only_mode = @old_spider_read_only_mode;
+--disable_query_log
+--disable_result_log
+--source ../../t/test_deinit.inc
+--enable_result_log
+--enable_query_log

storage/spider/spd_copy_tables.cc

@@ -64,12 +64,6 @@ int spider_udf_set_copy_tables_param_default(
     }
   }
 
-  if (copy_tables->bulk_insert_interval == -1)
-    copy_tables->bulk_insert_interval = 10;
-  if (copy_tables->bulk_insert_rows == -1)
-    copy_tables->bulk_insert_rows = 100;
-  if (copy_tables->use_table_charset == -1)
-    copy_tables->use_table_charset = 1;
   if (copy_tables->use_transaction == -1)
     copy_tables->use_transaction = 1;
 #ifndef WITHOUT_SPIDER_BG_SEARCH

storage/spider/spd_db_conn.cc

@@ -11559,7 +11559,7 @@ int spider_db_udf_copy_tables(
         error_num = result->get_errno();
         if (error_num == HA_ERR_END_OF_FILE)
         {
-          if (roop_count < copy_tables->bulk_insert_rows)
+          if (roop_count < bulk_insert_rows)
           {
             end_of_file = TRUE;
             if (roop_count)
@@ -11583,8 +11583,6 @@ int spider_db_udf_copy_tables(
               pthread_mutex_unlock(&tmp_conn->mta_conn_mutex);
               goto error_db_query;
             }
-            bulk_insert_rows = spider_param_udf_ct_bulk_insert_rows(
-              copy_tables->bulk_insert_rows);
             if (
               select_ct->append_key_order_str(key_info, 0, FALSE) ||
               select_ct->append_limit(0, bulk_insert_rows) ||

storage/spider/spd_direct_sql.cc

@@ -1451,25 +1451,10 @@ int spider_udf_set_direct_sql_param_default(
     }
   }
 
-  if (direct_sql->table_loop_mode == -1)
-    direct_sql->table_loop_mode = 0;
   if (direct_sql->priority == -1)
     direct_sql->priority = 1000000;
-  if (direct_sql->connect_timeout == -1)
-    direct_sql->connect_timeout = 6;
-  if (direct_sql->net_read_timeout == -1)
-    direct_sql->net_read_timeout = 600;
-  if (direct_sql->net_write_timeout == -1)
-    direct_sql->net_write_timeout = 600;
-  if (direct_sql->bulk_insert_rows == -1)
-    direct_sql->bulk_insert_rows = 3000;
   if (direct_sql->connection_channel == -1)
     direct_sql->connection_channel = 0;
-#if MYSQL_VERSION_ID < 50500
-#else
-  if (direct_sql->use_real_table == -1)
-    direct_sql->use_real_table = 0;
-#endif
   if (direct_sql->error_rw_mode == -1)
     direct_sql->error_rw_mode = 0;
   for (roop_count = 0; roop_count < direct_sql->table_count; roop_count++)