MDEV-34682 Reset spider_hton_ptr in error mode of spider_db_init()

storage/spider/mysql-test/spider/bugfix/r/mdev_34682.result

+set @old_aria_encrypt_tables=@@global.aria_encrypt_tables;
+set global aria_encrypt_tables=ON;
+CREATE FUNCTION spider_direct_sql RETURNS INT SONAME 'ha_spider.so';
+call mtr.add_suppression(".*\\[ERROR\\] SPIDER plugin initialization failed at.* by 'Initialization of encryption failed for");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER' registration as a STORAGE ENGINE failed.");
+INSTALL PLUGIN spider SONAME 'ha_spider.so';
+ERROR HY000: Can't initialize function 'spider'; Plugin initialization function failed.
+SELECT spider_direct_sql ('SELECT * FROM s','a','srv "b"');
+ERROR HY000: Can't initialize function 'spider_direct_sql'; Plugin 'SPIDER' is not loaded
+Warnings:
+Note	1305	FUNCTION test.spider_flush_table_mon_cache does not exist
+Warnings:
+Note	1305	FUNCTION test.spider_copy_tables does not exist
+Warnings:
+Note	1305	FUNCTION test.spider_ping_table does not exist
+Warnings:
+Note	1305	FUNCTION test.spider_bg_direct_sql does not exist
+Warnings:
+Note	1305	SONAME ha_spider.so does not exist

storage/spider/mysql-test/spider/bugfix/t/mdev_34682.test

+set @old_aria_encrypt_tables=@@global.aria_encrypt_tables;
+set global aria_encrypt_tables=ON;
+
+CREATE FUNCTION spider_direct_sql RETURNS INT SONAME 'ha_spider.so';
+call mtr.add_suppression(".*\\[ERROR\\] SPIDER plugin initialization failed at.* by 'Initialization of encryption failed for");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER' registration as a STORAGE ENGINE failed.");
+--error ER_CANT_INITIALIZE_UDF
+INSTALL PLUGIN spider SONAME 'ha_spider.so';
+--error ER_CANT_INITIALIZE_UDF
+SELECT spider_direct_sql ('SELECT * FROM s','a','srv "b"');
+
+--disable_query_log
+--source ../../include/clean_up_spider.inc
+set global aria_encrypt_tables=@old_aria_encrypt_tables;

storage/spider/mysql-test/spider/include/clean_up_spider.inc

-DROP FUNCTION spider_flush_table_mon_cache;
-DROP FUNCTION spider_copy_tables;
-DROP FUNCTION spider_ping_table;
-DROP FUNCTION spider_bg_direct_sql;
-DROP FUNCTION spider_direct_sql;
+DROP FUNCTION IF EXISTS spider_flush_table_mon_cache;
+DROP FUNCTION IF EXISTS spider_copy_tables;
+DROP FUNCTION IF EXISTS spider_ping_table;
+DROP FUNCTION IF EXISTS spider_bg_direct_sql;
+DROP FUNCTION IF EXISTS spider_direct_sql;
 UNINSTALL SONAME IF EXISTS 'ha_spider';
 DROP TABLE IF EXISTS mysql.spider_xa;
 DROP TABLE IF EXISTS mysql.spider_xa_member;

storage/spider/spd_table.cc

@@ -6805,6 +6805,7 @@ int spider_db_init(
   pthread_attr_destroy(&spider_pt_attr);
 error_pt_attr_init:
 #endif
+  spider_hton_ptr= NULL;
   DBUG_RETURN(error_num);
 }