diff --git a/mysql-test/r/trigger-trans.result b/mysql-test/r/trigger-trans.result
index cd5f629564f..dccaa27c5fd 100644
--- a/mysql-test/r/trigger-trans.result
+++ b/mysql-test/r/trigger-trans.result
@@ -140,4 +140,23 @@ select * from t3;
 c
 1
 drop table t1, t2, t3;
+DROP TABLE IF EXISTS t1;
+DROP TABLE IF EXISTS t2;
+CREATE TABLE t1(a INT PRIMARY KEY) ENGINE=innodb;
+CREATE TABLE t2(b INT, FOREIGN KEY(b) REFERENCES t1(a)) ENGINE=innodb;
+INSERT INTO t1 VALUES (1);
+CREATE TRIGGER t1_bd BEFORE DELETE ON t1 FOR EACH ROW SET @a = 1;
+CREATE TRIGGER t1_ad AFTER DELETE ON t1 FOR EACH ROW SET @b = 1;
+SET @a = 0;
+SET @b = 0;
+TRUNCATE t1;
+SELECT @a, @b;
+@a	@b
+0	0
+INSERT INTO t1 VALUES (1);
+DELETE FROM t1;
+SELECT @a, @b;
+@a	@b
+1	1
+DROP TABLE t2, t1;
 End of 5.0 tests
diff --git a/mysql-test/t/trigger-trans.test b/mysql-test/t/trigger-trans.test
index 8103a1ba0b1..5db5b982773 100644
--- a/mysql-test/t/trigger-trans.test
+++ b/mysql-test/t/trigger-trans.test
@@ -128,5 +128,37 @@ drop table t1, t2, t3;
 disconnect connection_update;
 disconnect connection_aux;
 
+#
+# Bug#34643: TRUNCATE crash if trigger and foreign key.
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+DROP TABLE IF EXISTS t2;
+--enable_warnings
+
+CREATE TABLE t1(a INT PRIMARY KEY) ENGINE=innodb;
+CREATE TABLE t2(b INT, FOREIGN KEY(b) REFERENCES t1(a)) ENGINE=innodb;
+
+INSERT INTO t1 VALUES (1);
+
+CREATE TRIGGER t1_bd BEFORE DELETE ON t1 FOR EACH ROW SET @a = 1;
+CREATE TRIGGER t1_ad AFTER DELETE ON t1 FOR EACH ROW SET @b = 1;
+
+SET @a = 0;
+SET @b = 0;
+
+TRUNCATE t1;
+
+SELECT @a, @b;
+
+INSERT INTO t1 VALUES (1);
+
+DELETE FROM t1;
+
+SELECT @a, @b;
+
+DROP TABLE t2, t1;
+
 
 --echo End of 5.0 tests
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index a28a39a769d..3019b68d6f1 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -35,6 +35,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   READ_RECORD	info;
   bool          using_limit=limit != HA_POS_ERROR;
   bool		transactional_table, safe_update, const_cond;
+  bool          triggers_applicable;
   ha_rows	deleted;
   uint usable_index= MAX_KEY;
   SELECT_LEX   *select_lex= &thd->lex->select_lex;
@@ -93,6 +94,11 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
 
   select_lex->no_error= thd->lex->ignore;
 
+  /* NOTE: TRUNCATE must not invoke triggers. */
+
+  triggers_applicable= table->triggers &&
+                       thd->lex->sql_command != SQLCOM_TRUNCATE;
+
   /*
     Test if the user wants to delete all rows and deletion doesn't have
     any side-effects (because of triggers), so we can use optimized
@@ -102,8 +108,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   */
   if (!using_limit && const_cond && (!conds || conds->val_int()) &&
       !(specialflag & (SPECIAL_NO_NEW_FUNC | SPECIAL_SAFE_MODE)) &&
-      (thd->lex->sql_command == SQLCOM_TRUNCATE ||
-       !(table->triggers && table->triggers->has_delete_triggers()))
+      !(triggers_applicable && table->triggers->has_delete_triggers())
      )
   {
     deleted= table->file->records;
@@ -217,7 +222,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   init_ftfuncs(thd, select_lex, 1);
   thd->proc_info="updating";
 
-  if (table->triggers)
+  if (triggers_applicable)
   {
     table->triggers->mark_fields_used(thd, TRG_EVENT_DELETE);
     if (table->triggers->has_triggers(TRG_EVENT_DELETE,
@@ -239,7 +244,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     if (!(select && select->skip_record())&& !thd->net.report_error )
     {
 
-      if (table->triggers &&
+      if (triggers_applicable &&
           table->triggers->process_triggers(thd, TRG_EVENT_DELETE,
                                             TRG_ACTION_BEFORE, FALSE))
       {
@@ -250,7 +255,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
       if (!(error=table->file->delete_row(table->record[0])))
       {
 	deleted++;
-        if (table->triggers &&
+        if (triggers_applicable &&
             table->triggers->process_triggers(thd, TRG_EVENT_DELETE,
                                               TRG_ACTION_AFTER, FALSE))
         {