Bug#30981 CHAR(0x41 USING ucs2) doesn't add leading zero

Bug#30982 CHAR(..USING..) can return a not-well-formed string
Bug#30986 Character set introducer followed by a HEX string can return bad result
check_well_formed_result moved to Item from Item_str_func
fixed Item_func_char::val_str for proper ucs symbols converting
added check for well formed strings for correct conversion of constants with underscore
charset


mysql-test/r/ctype_ucs.result:
  test result
mysql-test/r/ctype_utf8.result:
  test result
mysql-test/t/ctype_ucs.test:
  test case
mysql-test/t/ctype_utf8.test:
  test case
sql/item.cc:
  check_well_formed_result() moved from Item_str_func
sql/item.h:
  check_well_formed_result() moved from Item_str_func
sql/item_strfunc.cc:
  check_well_formed_result moved to Item
  fixed Item_func_char::val_str for proper ucs symbols converting
sql/item_strfunc.h:
  check_well_formed_result moved to Item
sql/sql_yacc.yy:
  added check for well formed string

2 files changed, 67 insertions, 2 deletions

diff --git a/mysql-test/r/ctype_ucs.result b/mysql-test/r/ctype_ucs.result
index 023267c227c..262055436b8 100644
--- a/mysql-test/r/ctype_ucs.result
+++ b/mysql-test/r/ctype_ucs.result
@@ -922,4 +922,7 @@ ERROR HY000: Illegal mix of collations (ascii_general_ci,IMPLICIT) and (ucs2_gen
 select * from t1 where a=if(b<10,_ucs2 0x0062,_ucs2 0x00C0);
 ERROR HY000: Illegal mix of collations (ascii_general_ci,IMPLICIT) and (ucs2_general_ci,COERCIBLE) for operation '='
 drop table t1;
+select hex(char(0x41 using ucs2));
+hex(char(0x41 using ucs2))
+0041
 End of 5.0 tests
diff --git a/mysql-test/r/ctype_utf8.result b/mysql-test/r/ctype_utf8.result
index 710cac388a5..a86dfbc190d 100644
--- a/mysql-test/r/ctype_utf8.result
+++ b/mysql-test/r/ctype_utf8.result
@@ -1538,12 +1538,12 @@ char(53647 using utf8)
 я
 select char(0xff,0x8f using utf8);
 char(0xff,0x8f using utf8)
-��
+
 Warnings:
 Warning	1300	Invalid utf8 character string: 'FF8F'
 select convert(char(0xff,0x8f) using utf8);
 convert(char(0xff,0x8f) using utf8)
-��
+
 Warnings:
 Warning	1300	Invalid utf8 character string: 'FF8F'
 set sql_mode=traditional;
@@ -1730,3 +1730,65 @@ i
 1
 н1234567890
 DROP TABLE t1, t2;
+set sql_mode=traditional;
+select hex(char(0xFF using utf8));
+hex(char(0xFF using utf8))
+NULL
+Warnings:
+Error	1300	Invalid utf8 character string: 'FF'
+select hex(convert(0xFF using utf8));
+hex(convert(0xFF using utf8))
+NULL
+Warnings:
+Error	1300	Invalid utf8 character string: 'FF'
+select hex(_utf8 0x616263FF);
+hex(_utf8 0x616263FF)
+NULL
+Warnings:
+Error	1300	Invalid utf8 character string: 'FF'
+select hex(_utf8 X'616263FF');
+hex(_utf8 X'616263FF')
+NULL
+Warnings:
+Error	1300	Invalid utf8 character string: 'FF'
+select hex(_utf8 B'001111111111');
+hex(_utf8 B'001111111111')
+NULL
+Warnings:
+Error	1300	Invalid utf8 character string: 'FF'
+select (_utf8 X'616263FF');
+(_utf8 X'616263FF')
+NULL
+Warnings:
+Error	1300	Invalid utf8 character string: 'FF'
+set sql_mode=default;
+select hex(char(0xFF using utf8));
+hex(char(0xFF using utf8))
+
+Warnings:
+Warning	1300	Invalid utf8 character string: 'FF'
+select hex(convert(0xFF using utf8));
+hex(convert(0xFF using utf8))
+
+Warnings:
+Warning	1300	Invalid utf8 character string: 'FF'
+select hex(_utf8 0x616263FF);
+hex(_utf8 0x616263FF)
+616263
+Warnings:
+Warning	1300	Invalid utf8 character string: 'FF'
+select hex(_utf8 X'616263FF');
+hex(_utf8 X'616263FF')
+616263
+Warnings:
+Warning	1300	Invalid utf8 character string: 'FF'
+select hex(_utf8 B'001111111111');
+hex(_utf8 B'001111111111')
+03
+Warnings:
+Warning	1300	Invalid utf8 character string: 'FF'
+select (_utf8 X'616263FF');
+(_utf8 X'616263FF')
+abc
+Warnings:
+Warning	1300	Invalid utf8 character string: 'FF'