MDEV-25659 trigger name is empty after upgrade to 10.4bb-10.4-bar-MDEV-25659

Problem:

At some point, we made stored rountines fail at CREATE time
instead of execution time in case of this syntax:

   IF unknown_variable
     ...
   END IF

As a result, a trigger created before this change and contained an unknown
variable worked in a bad way after upgrade:
- It was displayed with an empty trigger name by SHOW CREATE TRIGGER
- It was displayed with an empty trigger name by INFORMATION_SCHEMA.TRIGGERS
- An attempt to DROP this trigger returned errors - nothing happened.
- DROP TABLE did not remove the .TRN file corresponding to this broken trigger.

Underlying code observations:

The old code assumed that the trigger name resides in the current lex:

  if(thd->lex->spname)
    m_trigger_name= &thd->lex->spname->m_name;

This is not always the case. Some SP statements (e.g. IF)
do the following in their beginning:

- create a separate local LEX
- set thd->lex to this new local LEX
- push the new local LEX to the stack in sp_head::m_lex

and the following at the end of the statement:

- pop the previous LEX from the stack sp_head::m_lex
- set thd->lex back to the popped value

So when the parse error happens inside e.g. IF statement, thd->lex->spname
is a NULL pointer, because thd->lex points to the local LEX (without SP name)
rather than the top level LEX (with SP name).

Fix:
- Adding a new method sp_head::find_spname_recursive()
  which walks inside the LEX stack sp_head::m_lex from
  the top (the newest, most local) to the bottom (the oldest),
  and finds the one which contains a non-zero spname pointer.

- Using the new method inside
  Deprecated_trigger_syntax_handler::handle_condition():
  First it still tests thd->lex->spname (like before this change),
  and uses it in case it is not empty.
  Otherwise (if thd->lex->spname is empty), it calls
  sp_head::find_spname_recursive() to find the LEX with a
  non-empty spname inside the LEX stack of the current sphead.

4 files changed, 546 insertions, 3 deletions

diff --git a/mysql-test/main/trigger-compat.result b/mysql-test/main/trigger-compat.result
index 387d4fb1489..656edc63a7d 100644
--- a/mysql-test/main/trigger-compat.result
+++ b/mysql-test/main/trigger-compat.result
@@ -142,3 +142,298 @@ DROP TRIGGER tr12;
 DROP TRIGGER tr11;
 DROP TABLE t1;
 DROP TABLE t2;
+#
+# MDEV-25659 trigger name is empty after upgrade to 10.4
+#
+# START: Total triggers 1, broken triggers 1, DROP TABLE
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+FLUSH TABLES;
+DELETE FROM t1 WHERE a=1;
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+INSERT INTO t1 VALUES (2);
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+SET time_zone='+00:00';
+SHOW TRIGGERS LIKE 't1';
+Trigger	tr1
+Event	DELETE
+Table	t1
+Statement	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+Timing	AFTER
+Created	2022-01-13 08:23:06.47
+sql_mode	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+Definer	
+character_set_client	utf8
+collation_connection	utf8_general_ci
+Database Collation	latin1_swedish_ci
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+TRIGGER_CATALOG	def
+TRIGGER_SCHEMA	test
+TRIGGER_NAME	tr1
+EVENT_MANIPULATION	DELETE
+EVENT_OBJECT_CATALOG	def
+EVENT_OBJECT_SCHEMA	test
+EVENT_OBJECT_TABLE	t1
+ACTION_ORDER	1
+ACTION_CONDITION	NULL
+ACTION_STATEMENT	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+ACTION_ORIENTATION	ROW
+ACTION_TIMING	AFTER
+ACTION_REFERENCE_OLD_TABLE	NULL
+ACTION_REFERENCE_NEW_TABLE	NULL
+ACTION_REFERENCE_OLD_ROW	OLD
+ACTION_REFERENCE_NEW_ROW	NEW
+CREATED	2022-01-13 08:23:06.47
+SQL_MODE	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+DEFINER	
+CHARACTER_SET_CLIENT	utf8
+COLLATION_CONNECTION	utf8_general_ci
+DATABASE_COLLATION	latin1_swedish_ci
+SET time_zone=DEFAULT;
+# Listing trigger files
+t1.TRG
+tr1.TRN
+# Listing trigger files done
+DROP TABLE t1;
+# Listing trigger files
+# Listing trigger files done
+# END: Total triggers 1, broken triggers 1, DROP TABLE
+# START: Total triggers 1, broken triggers 1, DROP TRIGGER
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+FLUSH TABLES;
+DELETE FROM t1 WHERE a=1;
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+INSERT INTO t1 VALUES (2);
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+SET time_zone='+00:00';
+SHOW TRIGGERS LIKE 't1';
+Trigger	tr1
+Event	DELETE
+Table	t1
+Statement	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+Timing	AFTER
+Created	2022-01-13 08:23:06.47
+sql_mode	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+Definer	
+character_set_client	utf8
+collation_connection	utf8_general_ci
+Database Collation	latin1_swedish_ci
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+TRIGGER_CATALOG	def
+TRIGGER_SCHEMA	test
+TRIGGER_NAME	tr1
+EVENT_MANIPULATION	DELETE
+EVENT_OBJECT_CATALOG	def
+EVENT_OBJECT_SCHEMA	test
+EVENT_OBJECT_TABLE	t1
+ACTION_ORDER	1
+ACTION_CONDITION	NULL
+ACTION_STATEMENT	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+ACTION_ORIENTATION	ROW
+ACTION_TIMING	AFTER
+ACTION_REFERENCE_OLD_TABLE	NULL
+ACTION_REFERENCE_NEW_TABLE	NULL
+ACTION_REFERENCE_OLD_ROW	OLD
+ACTION_REFERENCE_NEW_ROW	NEW
+CREATED	2022-01-13 08:23:06.47
+SQL_MODE	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+DEFINER	
+CHARACTER_SET_CLIENT	utf8
+COLLATION_CONNECTION	utf8_general_ci
+DATABASE_COLLATION	latin1_swedish_ci
+SET time_zone=DEFAULT;
+# Listing trigger files
+t1.TRG
+tr1.TRN
+# Listing trigger files done
+DROP TRIGGER tr1;
+# Listing trigger files
+# Listing trigger files done
+DROP TABLE t1;
+# END: Total triggers 1, broken triggers 1, DROP TRIGGER
+# START: Total triggers 2, broken triggers 1, DROP TABLE
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+FLUSH TABLES;
+DELETE FROM t1 WHERE a=1;
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+INSERT INTO t1 VALUES (2);
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+SET time_zone='+00:00';
+SHOW TRIGGERS LIKE 't1';
+Trigger	tr2
+Event	INSERT
+Table	t1
+Statement	INSERT INTO t2 VALUES (NEW.a+100)
+Timing	AFTER
+Created	2022-01-13 10:01:48.74
+sql_mode	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+Definer	root@localhost
+character_set_client	utf8
+collation_connection	utf8_general_ci
+Database Collation	latin1_swedish_ci
+Trigger	tr1
+Event	DELETE
+Table	t1
+Statement	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+Timing	AFTER
+Created	2022-01-13 10:01:48.73
+sql_mode	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+Definer	
+character_set_client	utf8
+collation_connection	utf8_general_ci
+Database Collation	latin1_swedish_ci
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+TRIGGER_CATALOG	def
+TRIGGER_SCHEMA	test
+TRIGGER_NAME	tr1
+EVENT_MANIPULATION	DELETE
+EVENT_OBJECT_CATALOG	def
+EVENT_OBJECT_SCHEMA	test
+EVENT_OBJECT_TABLE	t1
+ACTION_ORDER	1
+ACTION_CONDITION	NULL
+ACTION_STATEMENT	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+ACTION_ORIENTATION	ROW
+ACTION_TIMING	AFTER
+ACTION_REFERENCE_OLD_TABLE	NULL
+ACTION_REFERENCE_NEW_TABLE	NULL
+ACTION_REFERENCE_OLD_ROW	OLD
+ACTION_REFERENCE_NEW_ROW	NEW
+CREATED	2022-01-13 10:01:48.73
+SQL_MODE	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+DEFINER	
+CHARACTER_SET_CLIENT	utf8
+COLLATION_CONNECTION	utf8_general_ci
+DATABASE_COLLATION	latin1_swedish_ci
+SET time_zone=DEFAULT;
+# Listing trigger files
+t1.TRG
+tr1.TRN
+tr2.TRN
+# Listing trigger files done
+DROP TABLE t1;
+# Listing trigger files
+# Listing trigger files done
+# END: Total triggers 2, broken triggers 1, using DROP TABLE
+# START: Total triggers 2, broken triggers 1, DROP TRIGGER
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+FLUSH TABLES;
+DELETE FROM t1 WHERE a=1;
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+INSERT INTO t1 VALUES (2);
+ERROR 42000: Trigger 'tr1' has an error in its body: 'Undeclared variable: unknown_variable'
+SET time_zone='+00:00';
+SHOW TRIGGERS LIKE 't1';
+Trigger	tr2
+Event	INSERT
+Table	t1
+Statement	INSERT INTO t2 VALUES (NEW.a+100)
+Timing	AFTER
+Created	2022-01-13 10:01:48.74
+sql_mode	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+Definer	root@localhost
+character_set_client	utf8
+collation_connection	utf8_general_ci
+Database Collation	latin1_swedish_ci
+Trigger	tr1
+Event	DELETE
+Table	t1
+Statement	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+Timing	AFTER
+Created	2022-01-13 10:01:48.73
+sql_mode	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+Definer	
+character_set_client	utf8
+collation_connection	utf8_general_ci
+Database Collation	latin1_swedish_ci
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+TRIGGER_CATALOG	def
+TRIGGER_SCHEMA	test
+TRIGGER_NAME	tr1
+EVENT_MANIPULATION	DELETE
+EVENT_OBJECT_CATALOG	def
+EVENT_OBJECT_SCHEMA	test
+EVENT_OBJECT_TABLE	t1
+ACTION_ORDER	1
+ACTION_CONDITION	NULL
+ACTION_STATEMENT	CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
+BEGIN
+  IF unknown_variable
+  THEN
+    INSERT INTO t2 VALUES (OLD.a);
+  END IF;
+END
+ACTION_ORIENTATION	ROW
+ACTION_TIMING	AFTER
+ACTION_REFERENCE_OLD_TABLE	NULL
+ACTION_REFERENCE_NEW_TABLE	NULL
+ACTION_REFERENCE_OLD_ROW	OLD
+ACTION_REFERENCE_NEW_ROW	NEW
+CREATED	2022-01-13 10:01:48.73
+SQL_MODE	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+DEFINER	
+CHARACTER_SET_CLIENT	utf8
+COLLATION_CONNECTION	utf8_general_ci
+DATABASE_COLLATION	latin1_swedish_ci
+SET time_zone=DEFAULT;
+# Listing trigger files
+t1.TRG
+tr1.TRN
+tr2.TRN
+# Listing trigger files done
+DROP TRIGGER tr1;
+# Listing trigger files
+t1.TRG
+tr2.TRN
+# Listing trigger files done
+INSERT INTO t1 VALUES (100);
+ERROR 42S02: Table 'test.t2' doesn't exist
+DROP TABLE t1;
+# Listing trigger files
+# Listing trigger files done
+# END: Total triggers 2, broken triggers 1, using DROP TRIGGER
diff --git a/mysql-test/main/trigger-compat.test b/mysql-test/main/trigger-compat.test
index baf3cad11d6..4d9160c7728 100644
--- a/mysql-test/main/trigger-compat.test
+++ b/mysql-test/main/trigger-compat.test
@@ -289,3 +289,219 @@ DROP TRIGGER tr11;
 
 DROP TABLE t1;
 DROP TABLE t2;
+
+
+--echo #
+--echo # MDEV-25659 trigger name is empty after upgrade to 10.4
+--echo #
+
+--echo # START: Total triggers 1, broken triggers 1, DROP TABLE
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+
+--write_file $MYSQLD_DATADIR/test/tr1.TRN
+TYPE=TRIGGERNAME
+trigger_table=t1
+EOF
+
+--write_file $MYSQLD_DATADIR/test/t1.TRG
+TYPE=TRIGGERS
+triggers='CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW\nBEGIN\n  IF unknown_variable\n  THEN\n    INSERT INTO t2 VALUES (OLD.a);\n  END IF;\nEND'
+sql_modes=1411383296
+definers='root@localhost'
+client_cs_names='utf8'
+connection_cl_names='utf8_general_ci'
+db_cl_names='latin1_swedish_ci'
+created=164206218647
+EOF
+
+FLUSH TABLES;
+--error ER_PARSE_ERROR
+DELETE FROM t1 WHERE a=1;
+--error ER_PARSE_ERROR
+INSERT INTO t1 VALUES (2);
+
+SET time_zone='+00:00';
+--vertical_results
+SHOW TRIGGERS LIKE 't1';
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+--horizontal_results
+SET time_zone=DEFAULT;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+DROP TABLE t1;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+--echo # END: Total triggers 1, broken triggers 1, DROP TABLE
+
+
+--echo # START: Total triggers 1, broken triggers 1, DROP TRIGGER
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+
+--write_file $MYSQLD_DATADIR/test/tr1.TRN
+TYPE=TRIGGERNAME
+trigger_table=t1
+EOF
+
+--write_file $MYSQLD_DATADIR/test/t1.TRG
+TYPE=TRIGGERS
+triggers='CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW\nBEGIN\n  IF unknown_variable\n  THEN\n    INSERT INTO t2 VALUES (OLD.a);\n  END IF;\nEND'
+sql_modes=1411383296
+definers='root@localhost'
+client_cs_names='utf8'
+connection_cl_names='utf8_general_ci'
+db_cl_names='latin1_swedish_ci'
+created=164206218647
+EOF
+
+FLUSH TABLES;
+--error ER_PARSE_ERROR
+DELETE FROM t1 WHERE a=1;
+--error ER_PARSE_ERROR
+INSERT INTO t1 VALUES (2);
+
+SET time_zone='+00:00';
+--vertical_results
+SHOW TRIGGERS LIKE 't1';
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+--horizontal_results
+SET time_zone=DEFAULT;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+DROP TRIGGER tr1;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+DROP TABLE t1;
+
+--echo # END: Total triggers 1, broken triggers 1, DROP TRIGGER
+
+
+--echo # START: Total triggers 2, broken triggers 1, DROP TABLE
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+
+--write_file $MYSQLD_DATADIR/test/tr1.TRN
+TYPE=TRIGGERNAME
+trigger_table=t1
+EOF
+
+--write_file $MYSQLD_DATADIR/test/tr2.TRN
+TYPE=TRIGGERNAME
+trigger_table=t1
+EOF
+
+--write_file $MYSQLD_DATADIR/test/t1.TRG
+TYPE=TRIGGERS
+triggers='CREATE DEFINER=`root`@`localhost` TRIGGER tr2 AFTER INSERT ON t1 FOR EACH ROW INSERT INTO t2 VALUES (NEW.a+100)' 'CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW\nBEGIN\n  IF unknown_variable\n  THEN\n    INSERT INTO t2 VALUES (OLD.a);\n  END IF;\nEND'
+sql_modes=1411383296 1411383296
+definers='root@localhost' 'root@localhost'
+client_cs_names='utf8' 'utf8'
+connection_cl_names='utf8_general_ci' 'utf8_general_ci'
+db_cl_names='latin1_swedish_ci' 'latin1_swedish_ci'
+created=164206810874 164206810873
+EOF
+
+FLUSH TABLES;
+--error ER_PARSE_ERROR
+DELETE FROM t1 WHERE a=1;
+--error ER_PARSE_ERROR
+INSERT INTO t1 VALUES (2);
+
+SET time_zone='+00:00';
+--vertical_results
+SHOW TRIGGERS LIKE 't1';
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+--horizontal_results
+SET time_zone=DEFAULT;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+DROP TABLE t1;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+--echo # END: Total triggers 2, broken triggers 1, using DROP TABLE
+
+
+--echo # START: Total triggers 2, broken triggers 1, DROP TRIGGER
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1);
+
+--write_file $MYSQLD_DATADIR/test/tr1.TRN
+TYPE=TRIGGERNAME
+trigger_table=t1
+EOF
+
+--write_file $MYSQLD_DATADIR/test/tr2.TRN
+TYPE=TRIGGERNAME
+trigger_table=t1
+EOF
+
+--write_file $MYSQLD_DATADIR/test/t1.TRG
+TYPE=TRIGGERS
+triggers='CREATE DEFINER=`root`@`localhost` TRIGGER tr2 AFTER INSERT ON t1 FOR EACH ROW INSERT INTO t2 VALUES (NEW.a+100)' 'CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW\nBEGIN\n  IF unknown_variable\n  THEN\n    INSERT INTO t2 VALUES (OLD.a);\n  END IF;\nEND'
+sql_modes=1411383296 1411383296
+definers='root@localhost' 'root@localhost'
+client_cs_names='utf8' 'utf8'
+connection_cl_names='utf8_general_ci' 'utf8_general_ci'
+db_cl_names='latin1_swedish_ci' 'latin1_swedish_ci'
+created=164206810874 164206810873
+EOF
+
+FLUSH TABLES;
+--error ER_PARSE_ERROR
+DELETE FROM t1 WHERE a=1;
+--error ER_PARSE_ERROR
+INSERT INTO t1 VALUES (2);
+
+SET time_zone='+00:00';
+--vertical_results
+SHOW TRIGGERS LIKE 't1';
+SELECT * FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='tr1';
+--horizontal_results
+SET time_zone=DEFAULT;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+DROP TRIGGER tr1;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+# Now we dropped the broken trigger. Make sure the good one is fired.
+# If everything goes as expected, it will try to insert into t2,
+# which does not exists, hence the (expected) error.
+--error ER_NO_SUCH_TABLE
+INSERT INTO t1 VALUES (100);
+
+DROP TABLE t1;
+
+--echo # Listing trigger files
+--list_files $MYSQLD_DATADIR/test *.TR?
+--echo # Listing trigger files done
+
+--echo # END: Total triggers 2, broken triggers 1, using DROP TRIGGER
diff --git a/sql/sp_head.h b/sql/sp_head.h
index 500446c5e16..69232da10c7 100644
--- a/sql/sp_head.h
+++ b/sql/sp_head.h
@@ -612,6 +612,23 @@ public:
     DBUG_RETURN(false);
   }
 
+  /**
+    Iterate through the LEX stack from the top (the newest) to the bottom
+    (the oldest) and find the one that contains a non-zero spname.
+    @returns - the address of spname, or NULL of no spname found.
+  */
+  const sp_name *find_spname_recursive()
+  {
+    uint count= m_lex.elements;
+    for (uint i= 0; i < count; i++)
+    {
+      const LEX *tmp= m_lex.elem(count - i - 1);
+      if (tmp->spname)
+        return tmp->spname;
+    }
+    return NULL;
+  }
+
   /// Put the instruction on the backpatch list, associated with the label.
   int
   push_backpatch(THD *thd, sp_instr *, sp_label *);
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 5802d2c811e..08cc2113706 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -292,7 +292,7 @@ class Deprecated_trigger_syntax_handler : public Internal_error_handler
 private:
 
   char m_message[MYSQL_ERRMSG_SIZE];
-  LEX_CSTRING *m_trigger_name;
+  const LEX_CSTRING *m_trigger_name;
 
 public:
 
@@ -308,8 +308,23 @@ public:
     if (sql_errno != EE_OUTOFMEMORY &&
         sql_errno != ER_OUT_OF_RESOURCES)
     {
+      // Check if the current LEX contains a non-empty spname
       if(thd->lex->spname)
         m_trigger_name= &thd->lex->spname->m_name;
+      else if (thd->lex->sphead)
+      {
+        /*
+          Some SP statements, for example IF, create their own local LEX.
+          All LEX instances are available in the LEX stack in sphead::m_lex.
+          Let's find the one that contains a non-zero spname.
+          Note, although a parse error has happened, the LEX instances
+          in sphead::m_lex are not freed yet at this point. The first
+          found non-zero spname contains the valid trigger name.
+        */
+        const sp_name *spname= thd->lex->sphead->find_spname_recursive();
+        if (spname)
+          m_trigger_name= &spname->m_name;
+      }
       if (m_trigger_name)
         my_snprintf(m_message, sizeof(m_message),
                     ER_THD(thd, ER_ERROR_IN_TRIGGER_BODY),
@@ -322,7 +337,7 @@ public:
     return false;
   }
 
-  LEX_CSTRING *get_trigger_name() { return m_trigger_name; }
+  const LEX_CSTRING *get_trigger_name() { return m_trigger_name; }
   char *get_error_message() { return m_message; }
 };
 
@@ -1490,7 +1505,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const LEX_CSTRING *db,
 
         if (unlikely(parse_error))
         {
-          LEX_CSTRING *name;
+          const LEX_CSTRING *name;
 
           /*
             In case of errors, disable all triggers for the table, but keep