diff --git a/mysql-test/r/ctype_collate.result b/mysql-test/r/ctype_collate.result
index e3130888a05..66266d40fb3 100644
--- a/mysql-test/r/ctype_collate.result
+++ b/mysql-test/r/ctype_collate.result
@@ -535,6 +535,19 @@ s2 CHAR(5) COLLATE latin1_swedish_ci);
 SELECT * FROM t1 WHERE s1 = s2;
 ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_swedish_ci,IMPLICIT) for operation '='
 DROP TABLE t1;
+CREATE TABLE t1
+(s1 CHAR(5) COLLATE latin1_german1_ci,
+s2 CHAR(5) COLLATE latin1_swedish_ci,
+s3 CHAR(5) COLLATE latin1_bin);
+INSERT INTO t1 VALUES ('a','A','A');
+SELECT * FROM t1 WHERE s1 = s2;
+ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_swedish_ci,IMPLICIT) for operation '='
+SELECT * FROM t1 WHERE s1 = s3;
+s1	s2	s3
+SELECT * FROM t1 WHERE s2 = s3;
+s1	s2	s3
+a	A	A
+DROP TABLE t1;
 SET NAMES latin1;
 CREATE TABLE t1 
 (s1 char(10) COLLATE latin1_german1_ci,
diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result
index c5295048126..dcd364f1422 100644
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -1103,7 +1103,7 @@ count(*)
 drop table t1;
 create table t2 (
 a char character set latin1 collate latin1_swedish_ci,
-b char character set latin1 collate latin1_bin);
+b char character set latin1 collate latin1_german1_ci);
 create table t1 as
 (select a from t2) union
 (select b from t2);
diff --git a/mysql-test/t/ctype_collate.test b/mysql-test/t/ctype_collate.test
index 3599beeacc4..b65067a36cf 100644
--- a/mysql-test/t/ctype_collate.test
+++ b/mysql-test/t/ctype_collate.test
@@ -158,6 +158,18 @@ SELECT * FROM t1 WHERE s1 = s2;
 DROP TABLE t1;
 
 
+CREATE TABLE t1
+(s1 CHAR(5) COLLATE latin1_german1_ci,
+ s2 CHAR(5) COLLATE latin1_swedish_ci,
+ s3 CHAR(5) COLLATE latin1_bin);
+INSERT INTO t1 VALUES ('a','A','A');
+--error 1267
+SELECT * FROM t1 WHERE s1 = s2;
+SELECT * FROM t1 WHERE s1 = s3;
+SELECT * FROM t1 WHERE s2 = s3;
+DROP TABLE t1;
+
+
 #
 # Test that optimizer doesn't use indexes with wrong collation
 #
diff --git a/mysql-test/t/union.test b/mysql-test/t/union.test
index 7d3f52bd7ae..239a7aaad4b 100644
--- a/mysql-test/t/union.test
+++ b/mysql-test/t/union.test
@@ -659,7 +659,7 @@ drop table t1;
 
 create table t2 (
 a char character set latin1 collate latin1_swedish_ci,
-b char character set latin1 collate latin1_bin);
+b char character set latin1 collate latin1_german1_ci);
 --error 1271
 create table t1 as
 (select a from t2) union
diff --git a/sql/ha_innodb.cc b/sql/ha_innodb.cc
index cfc649a5963..5ffa9e26ea2 100644
--- a/sql/ha_innodb.cc
+++ b/sql/ha_innodb.cc
@@ -5380,6 +5380,32 @@ ha_innobase::get_foreign_key_list(THD *thd, List<FOREIGN_KEY_INFO> *f_key_list)
   DBUG_RETURN(0);
 }
 
+/*********************************************************************
+Checks if ALTER TABLE may change the storage engine of the table.
+Changing storage engines is not allowed for tables for which there
+are foreign key constraints (parent or child tables). */
+
+bool
+ha_innobase::can_switch_engines(void)
+/*=================================*/
+{
+	row_prebuilt_t* prebuilt	= (row_prebuilt_t*) innobase_prebuilt;
+	bool	can_switch;
+
+ 	DBUG_ENTER("ha_innobase::can_switch_engines");
+	prebuilt->trx->op_info =
+			"determining if there are foreign key constraints";
+	row_mysql_lock_data_dictionary(prebuilt->trx);
+
+	can_switch = !UT_LIST_GET_FIRST(prebuilt->table->referenced_list)
+			&& !UT_LIST_GET_FIRST(prebuilt->table->foreign_list);
+
+	row_mysql_unlock_data_dictionary(prebuilt->trx);
+	prebuilt->trx->op_info = "";
+
+	DBUG_RETURN(can_switch);
+}
+
 /***********************************************************************
 Checks if a table is referenced by a foreign key. The MySQL manual states that
 a REPLACE is either equivalent to an INSERT, or DELETE(s) + INSERT. Only a
diff --git a/sql/ha_innodb.h b/sql/ha_innodb.h
index a5714769bc5..ff3014ece1e 100644
--- a/sql/ha_innodb.h
+++ b/sql/ha_innodb.h
@@ -179,6 +179,7 @@ class ha_innobase: public handler
         char* update_table_comment(const char* comment);
 	char* get_foreign_key_create_info();
         int get_foreign_key_list(THD *thd, List<FOREIGN_KEY_INFO> *f_key_list);
+	bool can_switch_engines();
   	uint referenced_by_foreign_key();
 	void free_foreign_key_create_info(char* str);	
   	THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
diff --git a/sql/handler.h b/sql/handler.h
index c9a7d17e6dc..5d26bca241a 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -671,6 +671,8 @@ public:
   virtual void append_create_info(String *packet) {}
   virtual char* get_foreign_key_create_info()
   { return(NULL);}  /* gets foreign key create string from InnoDB */
+  /* used in ALTER TABLE; 1 if changing storage engine is allowed */
+  virtual bool can_switch_engines() { return 1; }
   /* used in REPLACE; is > 0 if table is referred by a FOREIGN KEY */
   virtual int get_foreign_key_list(THD *thd, List<FOREIGN_KEY_INFO> *f_key_list)
   { return 0; }
diff --git a/sql/item.cc b/sql/item.cc
index 636b6f3cfc8..d24cc6cbf51 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -936,8 +936,17 @@ bool DTCollation::aggregate(DTCollation &dt, uint flags)
 	set(0, DERIVATION_NONE);
 	return 1;
       }
+      if (collation->state & MY_CS_BINSORT)
+      {
+        return 0;
+      }
+      else if (dt.collation->state & MY_CS_BINSORT)
+      {
+        set(dt);
+        return 0;
+      }
       CHARSET_INFO *bin= get_charset_by_csname(collation->csname, 
-					       MY_CS_BINSORT,MYF(0));
+                                               MY_CS_BINSORT,MYF(0));
       set(bin, DERIVATION_NONE);
     }
   }
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 4b40ff7638c..31a544368e5 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -3302,6 +3302,10 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
   /* Safety fix for innodb */
   if (lower_case_table_names)
     my_casedn_str(files_charset_info, tmp_name);
+  if (new_db_type != old_db_type && !table->file->can_switch_engines()) {
+    my_error(ER_ROW_IS_REFERENCED, MYF(0));
+    goto err;
+  }
   create_info->db_type=new_db_type;
   if (!create_info->comment)
     create_info->comment= table->s->comment;