diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c
index c8e2d48873f..3f4820f4bc1 100644
--- a/libmysql/libmysql.c
+++ b/libmysql/libmysql.c
@@ -4352,6 +4352,7 @@ static my_bool setup_one_fetch_function(MYSQL_BIND *param, MYSQL_FIELD *field)
   case MYSQL_TYPE_STRING:
   case MYSQL_TYPE_DECIMAL:
   case MYSQL_TYPE_NEWDECIMAL:
+  case MYSQL_TYPE_NEWDATE:
     DBUG_ASSERT(param->buffer_length != 0);
     param->fetch_result= fetch_result_str;
     break;
@@ -4424,6 +4425,7 @@ static my_bool setup_one_fetch_function(MYSQL_BIND *param, MYSQL_FIELD *field)
   case MYSQL_TYPE_VAR_STRING:
   case MYSQL_TYPE_STRING:
   case MYSQL_TYPE_BIT:
+  case MYSQL_TYPE_NEWDATE:
     param->skip_result= skip_result_string;
     break;
   default:
diff --git a/mysql-test/r/date_formats.result b/mysql-test/r/date_formats.result
index c1c8b7b060e..fbe46e9fa21 100644
--- a/mysql-test/r/date_formats.result
+++ b/mysql-test/r/date_formats.result
@@ -478,7 +478,7 @@ str_to_date(a,b)
 create table t2 select str_to_date(a,b) from t1;
 describe t2;
 Field	Type	Null	Key	Default	Extra
-str_to_date(a,b)	binary(29)	YES		NULL	
+str_to_date(a,b)	datetime	YES		NULL	
 select str_to_date("2003-01-02 10:11:12.0012", "%Y-%m-%d %H:%i:%S.%f") as f1,
 str_to_date("2003-01-02 10:11:12.0012", "%Y-%m-%d %H:%i:%S") as f2,
 str_to_date("2003-01-02", "%Y-%m-%d") as f3,
diff --git a/mysql-test/r/insert_select.result b/mysql-test/r/insert_select.result
index 2604e4bf648..780e91ea73f 100644
--- a/mysql-test/r/insert_select.result
+++ b/mysql-test/r/insert_select.result
@@ -816,3 +816,15 @@ id	prev_id	join_id
 3	2	0
 4	3	0
 DROP TABLE t1,t2;
+#
+# Bug#30384: Having SQL_BUFFER_RESULT option in the
+#            CREATE .. KEY(..) .. SELECT led to creating corrupted index.
+#
+create table t1(f1 int);
+insert into t1 values(1),(2),(3);
+create table t2 (key(f1)) engine=myisam select sql_buffer_result f1 from t1;
+check table t2 extended;
+Table	Op	Msg_type	Msg_text
+test.t2	check	status	OK
+drop table t1,t2;
+##################################################################
diff --git a/mysql-test/r/type_datetime.result b/mysql-test/r/type_datetime.result
index ffe4bac142d..cf9df0dec4d 100644
--- a/mysql-test/r/type_datetime.result
+++ b/mysql-test/r/type_datetime.result
@@ -427,6 +427,67 @@ f1
 Warnings:
 Warning	1292	Incorrect datetime value: '2007010100000' for column 'f1' at row 1
 drop table t1;
+#
+# Bug#27216: functions with parameters of different date types may
+#            return wrong type of the result.
+#
+create table t1 (f1 date, f2 datetime, f3 varchar(20));
+create table t2 as select coalesce(f1,f1) as f4 from t1;
+desc t2;
+Field	Type	Null	Key	Default	Extra
+f4	date	YES		NULL	
+create table t3 as select coalesce(f1,f2) as f4 from t1;
+desc t3;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t4 as select coalesce(f2,f2) as f4 from t1;
+desc t4;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t5 as select coalesce(f1,f3) as f4 from t1;
+desc t5;
+Field	Type	Null	Key	Default	Extra
+f4	varbinary(20)	YES		NULL	
+create table t6 as select coalesce(f2,f3) as f4 from t1;
+desc t6;
+Field	Type	Null	Key	Default	Extra
+f4	varbinary(20)	YES		NULL	
+create table t7 as select coalesce(makedate(1997,1),f2) as f4 from t1;
+desc t7;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t8 as select coalesce(cast('01-01-01' as datetime),f2) as f4
+from t1;
+desc t8;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t9 as select case when 1 then cast('01-01-01' as date)
+when 0 then cast('01-01-01' as date) end as f4 from t1;
+desc t9;
+Field	Type	Null	Key	Default	Extra
+f4	date	YES		NULL	
+create table t10 as select case when 1 then cast('01-01-01' as datetime)
+when 0 then cast('01-01-01' as datetime) end as f4 from t1;
+desc t10;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t11 as select if(1, cast('01-01-01' as datetime),
+cast('01-01-01' as date)) as f4 from t1;
+desc t11;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t12 as select least(cast('01-01-01' as datetime),
+cast('01-01-01' as date)) as f4 from t1;
+desc t12;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+create table t13 as select ifnull(cast('01-01-01' as datetime),
+cast('01-01-01' as date)) as f4 from t1;
+desc t13;
+Field	Type	Null	Key	Default	Extra
+f4	datetime	YES		NULL	
+drop tables t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13;
+###################################################################
 set @org_mode=@@sql_mode;
 create table t1 (da date default '1962-03-03 23:33:34', dt datetime default '1962-03-03');
 Warnings:
diff --git a/mysql-test/t/insert_select.test b/mysql-test/t/insert_select.test
index ace51ef61c7..499db086877 100644
--- a/mysql-test/t/insert_select.test
+++ b/mysql-test/t/insert_select.test
@@ -372,3 +372,15 @@ INSERT INTO t1 (prev_id) SELECT id
 SELECT * FROM t1;
 
 DROP TABLE t1,t2;
+
+--echo #
+--echo # Bug#30384: Having SQL_BUFFER_RESULT option in the
+--echo #            CREATE .. KEY(..) .. SELECT led to creating corrupted index.
+--echo #
+create table t1(f1 int);
+insert into t1 values(1),(2),(3);
+create table t2 (key(f1)) engine=myisam select sql_buffer_result f1 from t1;
+check table t2 extended;
+drop table t1,t2;
+--echo ##################################################################
+
diff --git a/mysql-test/t/type_datetime.test b/mysql-test/t/type_datetime.test
index d8d137d81e6..961b052c039 100644
--- a/mysql-test/t/type_datetime.test
+++ b/mysql-test/t/type_datetime.test
@@ -283,6 +283,43 @@ select * from t1 where f1 between 2002010 and 20070101000000;
 select * from t1 where f1 between 20020101 and 2007010100000;
 drop table t1;
 
+--echo #
+--echo # Bug#27216: functions with parameters of different date types may
+--echo #            return wrong type of the result.
+--echo #
+create table t1 (f1 date, f2 datetime, f3 varchar(20));
+create table t2 as select coalesce(f1,f1) as f4 from t1;
+desc t2;
+create table t3 as select coalesce(f1,f2) as f4 from t1;
+desc t3;
+create table t4 as select coalesce(f2,f2) as f4 from t1;
+desc t4;
+create table t5 as select coalesce(f1,f3) as f4 from t1;
+desc t5;
+create table t6 as select coalesce(f2,f3) as f4 from t1;
+desc t6;
+create table t7 as select coalesce(makedate(1997,1),f2) as f4 from t1;
+desc t7;
+create table t8 as select coalesce(cast('01-01-01' as datetime),f2) as f4
+  from t1;
+desc t8;
+create table t9 as select case when 1 then cast('01-01-01' as date)
+  when 0 then cast('01-01-01' as date) end as f4 from t1;
+desc t9;
+create table t10 as select case when 1 then cast('01-01-01' as datetime)
+  when 0 then cast('01-01-01' as datetime) end as f4 from t1;
+desc t10;
+create table t11 as select if(1, cast('01-01-01' as datetime),
+  cast('01-01-01' as date)) as f4 from t1;
+desc t11;
+create table t12 as select least(cast('01-01-01' as datetime),
+  cast('01-01-01' as date)) as f4 from t1;
+desc t12;
+create table t13 as select ifnull(cast('01-01-01' as datetime),
+  cast('01-01-01' as date)) as f4 from t1;
+desc t13;
+drop tables t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13;
+--echo ###################################################################
 #
 # Test of storing datetime into date fields
 #
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 8f5ff050dd6..690661bc513 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -146,6 +146,35 @@ static int agg_cmp_type(Item_result *type, Item **items, uint nitems)
 }
 
 
+/**
+  @brief Aggregates field types from the array of items.
+
+  @param[in] items  array of items to aggregate the type from
+  @paran[in] nitems number of items in the array
+
+  @details This function aggregates field types from the array of items.
+    Found type is supposed to be used later as the result field type
+    of a multi-argument function.
+    Aggregation itself is performed by the Field::field_type_merge()
+    function.
+
+  @note The term "aggregation" is used here in the sense of inferring the
+    result type of a function from its argument types.
+
+  @return aggregated field type.
+*/
+
+enum_field_types agg_field_type(Item **items, uint nitems)
+{
+  uint i;
+  if (!nitems || items[0]->result_type() == ROW_RESULT )
+    return (enum_field_types)-1;
+  enum_field_types res= items[0]->field_type();
+  for (i= 1 ; i < nitems ; i++)
+    res= Field::field_type_merge(res, items[i]->field_type());
+  return res;
+}
+
 /*
   Collects different types for comparison of first item with each other items
 
@@ -2065,9 +2094,7 @@ Item_func_ifnull::fix_length_and_dec()
   default:
     DBUG_ASSERT(0);
   }
-  cached_field_type= args[0]->field_type();
-  if (cached_field_type != args[1]->field_type())
-    cached_field_type= Item_func::field_type();
+  cached_field_type= agg_field_type(args, 2);
 }
 
 
@@ -2215,11 +2242,13 @@ Item_func_if::fix_length_and_dec()
   {
     cached_result_type= arg2_type;
     collation.set(args[2]->collation.collation);
+    cached_field_type= args[2]->field_type();
   }
   else if (null2)
   {
     cached_result_type= arg1_type;
     collation.set(args[1]->collation.collation);
+    cached_field_type= args[1]->field_type();
   }
   else
   {
@@ -2233,6 +2262,7 @@ Item_func_if::fix_length_and_dec()
     {
       collation.set(&my_charset_bin);	// Number
     }
+    cached_field_type= agg_field_type(args + 1, 2);
   }
 
   if ((cached_result_type == DECIMAL_RESULT )
@@ -2582,7 +2612,7 @@ void Item_func_case::fix_length_and_dec()
       agg_arg_charsets(collation, agg, nagg, MY_COLL_ALLOW_CONV, 1))
     return;
   
-  
+  cached_field_type= agg_field_type(agg, nagg);
   /*
     Aggregate first expression and all THEN expression types
     and collations when string comparison
@@ -2751,6 +2781,7 @@ my_decimal *Item_func_coalesce::decimal_op(my_decimal *decimal_value)
 
 void Item_func_coalesce::fix_length_and_dec()
 {
+  cached_field_type= agg_field_type(args, arg_count);
   agg_result_type(&hybrid_type, args, arg_count);
   switch (hybrid_type) {
   case STRING_RESULT:
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 40d0c2dfe91..1a64f9c4211 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -640,6 +640,7 @@ public:
 class Item_func_coalesce :public Item_func_numhybrid
 {
 protected:
+  enum_field_types cached_field_type;
   Item_func_coalesce(Item *a, Item *b) :Item_func_numhybrid(a, b) {}
 public:
   Item_func_coalesce(List<Item> &list) :Item_func_numhybrid(list) {}
@@ -652,13 +653,13 @@ public:
   enum Item_result result_type () const { return hybrid_type; }
   const char *func_name() const { return "coalesce"; }
   table_map not_null_tables() const { return 0; }
+  enum_field_types field_type() const { return cached_field_type; }
 };
 
 
 class Item_func_ifnull :public Item_func_coalesce
 {
 protected:
-  enum_field_types cached_field_type;
   bool field_type_defined;
 public:
   Item_func_ifnull(Item *a, Item *b) :Item_func_coalesce(a,b) {}
@@ -677,6 +678,7 @@ public:
 class Item_func_if :public Item_func
 {
   enum Item_result cached_result_type;
+  enum_field_types cached_field_type;
 public:
   Item_func_if(Item *a,Item *b,Item *c)
     :Item_func(a,b,c), cached_result_type(INT_RESULT)
@@ -686,6 +688,7 @@ public:
   String *val_str(String *str);
   my_decimal *val_decimal(my_decimal *);
   enum Item_result result_type () const { return cached_result_type; }
+  enum_field_types field_type() const { return cached_field_type; }
   bool fix_fields(THD *, Item **);
   void fix_length_and_dec();
   uint decimal_precision() const;
@@ -713,6 +716,7 @@ public:
   bool is_null();
 };
 
+
 /* Functions to handle the optimized IN */
 
 
@@ -1442,6 +1446,7 @@ public:
   Item *transform(Item_transformer transformer, uchar *arg);
   void traverse_cond(Cond_traverser, void *arg, traverse_order order);
   void neg_arguments(THD *thd);
+  enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
   bool subst_argument_checker(uchar **arg) { return TRUE; }
   Item *compile(Item_analyzer analyzer, uchar **arg_p,
                 Item_transformer transformer, uchar *arg_t);
diff --git a/sql/item_func.cc b/sql/item_func.cc
index efc42c1b73f..6b1c0e340a5 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -2238,6 +2238,7 @@ void Item_func_min_max::fix_length_and_dec()
   else if ((cmp_type == DECIMAL_RESULT) || (cmp_type == INT_RESULT))
     max_length= my_decimal_precision_to_length(max_int_part+decimals, decimals,
                                             unsigned_flag);
+  cached_field_type= agg_field_type(args, arg_count);
 }
 
 
diff --git a/sql/item_func.h b/sql/item_func.h
index ea22e35773d..602c1c86f01 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -699,7 +699,8 @@ class Item_func_min_max :public Item_func
   /* An item used for issuing warnings while string to DATETIME conversion. */
   Item *datetime_item;
   THD *thd;
-
+protected:
+  enum_field_types cached_field_type;
 public:
   Item_func_min_max(List<Item> &list,int cmp_sign_arg) :Item_func(list),
     cmp_type(INT_RESULT), cmp_sign(cmp_sign_arg), compare_as_dates(FALSE),
@@ -712,6 +713,7 @@ public:
   enum Item_result result_type () const { return cmp_type; }
   bool result_as_longlong() { return compare_as_dates; };
   uint cmp_datetimes(ulonglong *value);
+  enum_field_types field_type() const { return cached_field_type; }
 };
 
 class Item_func_min :public Item_func_min_max
diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index 300d0788f55..59e1777f542 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -3239,7 +3239,7 @@ void Item_func_str_to_date::fix_length_and_dec()
   String format_str(format_buff, sizeof(format_buff), &my_charset_bin), *format;
   maybe_null= 1;
   decimals=0;
-  cached_field_type= MYSQL_TYPE_STRING;
+  cached_field_type= MYSQL_TYPE_DATETIME;
   max_length= MAX_DATETIME_FULL_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
   cached_timestamp_type= MYSQL_TIMESTAMP_NONE;
   format= args[1]->val_str(&format_str);
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 47a42354423..3aaee71bd42 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -1673,6 +1673,7 @@ void flush_thread_cache();
 
 /* item_func.cc */
 extern bool check_reserved_words(LEX_STRING *name);
+extern enum_field_types agg_field_type(Item **items, uint nitems);
 
 /* strfunc.cc */
 ulonglong find_set(TYPELIB *lib, const char *x, uint length, CHARSET_INFO *cs,
diff --git a/sql/protocol.cc b/sql/protocol.cc
index 2ed241c4c98..839109ef964 100644
--- a/sql/protocol.cc
+++ b/sql/protocol.cc
@@ -827,6 +827,7 @@ bool Protocol_text::store(const char *from, size_t length,
 	      field_types[field_pos] == MYSQL_TYPE_DECIMAL ||
               field_types[field_pos] == MYSQL_TYPE_BIT ||
               field_types[field_pos] == MYSQL_TYPE_NEWDECIMAL ||
+              field_types[field_pos] == MYSQL_TYPE_NEWDATE ||
 	      (field_types[field_pos] >= MYSQL_TYPE_ENUM &&
 	       field_types[field_pos] <= MYSQL_TYPE_GEOMETRY));
   field_pos++;
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 7875870bd1a..95338d7f151 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -2107,7 +2107,7 @@ class select_insert :public select_result_interceptor {
   ulonglong autoinc_value_of_last_inserted_row; // autogenerated or not
   COPY_INFO info;
   bool insert_into_view;
-
+  bool is_bulk_insert_mode;
   select_insert(TABLE_LIST *table_list_par,
 		TABLE *table_par, List<Item> *fields_par,
 		List<Item> *update_fields, List<Item> *update_values,
diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index ebbf4cafb19..4bac5f9c9da 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -2778,7 +2778,8 @@ select_insert::select_insert(TABLE_LIST *table_list_par, TABLE *table_par,
                              bool ignore_check_option_errors)
   :table_list(table_list_par), table(table_par), fields(fields_par),
    autoinc_value_of_last_inserted_row(0),
-   insert_into_view(table_list_par && table_list_par->view != 0)
+   insert_into_view(table_list_par && table_list_par->view != 0),
+   is_bulk_insert_mode(FALSE)
 {
   bzero((char*) &info,sizeof(info));
   info.handle_duplicates= duplic;
@@ -2964,8 +2965,11 @@ int select_insert::prepare2(void)
 {
   DBUG_ENTER("select_insert::prepare2");
   if (thd->lex->current_select->options & OPTION_BUFFER_RESULT &&
-      !thd->prelocked_mode)
+      !thd->prelocked_mode && !is_bulk_insert_mode)
+  {
     table->file->ha_start_bulk_insert((ha_rows) 0);
+    is_bulk_insert_mode= TRUE;
+  }
   DBUG_RETURN(0);
 }
 
@@ -3084,6 +3088,7 @@ bool select_insert::send_eof()
                        trans_table, table->file->table_type()));
 
   error= (!thd->prelocked_mode) ? table->file->ha_end_bulk_insert():0;
+  is_bulk_insert_mode= FALSE;
   table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
   table->file->extra(HA_EXTRA_WRITE_CANNOT_REPLACE);
 
@@ -3307,7 +3312,10 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info,
     Create_field *cr_field;
     Field *field, *def_field;
     if (item->type() == Item::FUNC_ITEM)
-      field= item->tmp_table_field(&tmp_table);
+      if (item->result_type() != STRING_RESULT)
+        field= item->tmp_table_field(&tmp_table);
+      else
+        field= item->tmp_table_field_from_field_type(&tmp_table);
     else
       field= create_tmp_field(thd, &tmp_table, item, item->type(),
                               (Item ***) 0, &tmp_field, &def_field, 0, 0, 0, 0,
@@ -3518,7 +3526,10 @@ select_create::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
   if (info.handle_duplicates == DUP_UPDATE)
     table->file->extra(HA_EXTRA_INSERT_WITH_UPDATE);
   if (!thd->prelocked_mode)
+  {
     table->file->ha_start_bulk_insert((ha_rows) 0);
+    is_bulk_insert_mode= TRUE;
+  }
   thd->abort_on_warning= (!info.ignore &&
                           (thd->variables.sql_mode &
                            (MODE_STRICT_TRANS_TABLES |