MDEV-22380: Assertion `name.length == strlen(name.str)' failed ...

Also fixes:
MDEV-25399 Assertion `name.length == strlen(name.str)' failed in Item_func_sp::make_send_field

Also fixes a problem that in this scenario:

SET NAMES binary;
SELECT 'some not well-formed utf8 string';

the auto-generated column name copied the binary string value directly
to the Item name, without checking utf8 well-formedness.

After this change auto-generated column names work as follows:
- Zero bytes 0x00 are copied to the name using HEX notation
- In case of "SET NAMES binary", all bytes sequences that do not make
  well-formed utf8 characters are copied to the name using HEX notation.

mysql-test/main/alias.result

@@ -218,3 +218,154 @@ DELETE ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
 ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 't1 WHERE 1=1' at line 1
 connection default;
 disconnect c1;
+#
+# MDEV-25399 Assertion `name.length == strlen(name.str)' failed in Item_func_sp::make_send_field
+#
+SET sql_mode='';
+CREATE FUNCTION f(i INT) RETURNS INT RETURN 1;
+PREPARE s FROM "SELECT f('\0')";
+EXECUTE s;
+f('\x00')
+1
+DROP FUNCTION f;
+SET sql_mode=DEFAULT;
+#
+# MDEV-22380: Assertion `name.length == strlen(name.str)' failed
+# in Item::print_item_w_name on SELECT w/ optimizer_trace enabled
+#
+SELECT '' LIMIT 0;
+
+CREATE TABLE t1 AS SELECT '';
+ERROR 42000: Incorrect column name ''
+CREATE PROCEDURE test_inject(arg TEXT CHARACTER SET latin1)
+BEGIN
+SET @stmt=CONCAT('SELECT ''', arg, ''', CONCAT(''', arg, ''') LIMIT 0');
+PREPARE stmt FROM @stmt;
+EXECUTE stmt;
+SET @stmt=CONCAT('CREATE TABLE t1 AS ', @stmt);
+PREPARE stmt FROM @stmt;
+EXECUTE stmt;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+END;
+$$
+SELECT x'FF32', CONCAT(x'FF32') LIMIT 0;
+x'FF32'	CONCAT(x'FF32')
+CREATE TABLE t1 AS SELECT x'FF32', CONCAT(x'FF32');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `x'FF32'` varbinary(2) NOT NULL,
+  `CONCAT(x'FF32')` varbinary(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject(x'FF32');
+2	CONCAT('2')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `2` varchar(2) NOT NULL,
+  `CONCAT('2')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT x'32FF', CONCAT(x'32FF') LIMIT 0;
+x'32FF'	CONCAT(x'32FF')
+CREATE TABLE t1 AS SELECT x'32FF', CONCAT(x'32FF');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `x'32FF'` varbinary(2) NOT NULL,
+  `CONCAT(x'32FF')` varbinary(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject(x'32FF');
+2	CONCAT('2')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `2` varchar(2) NOT NULL,
+  `CONCAT('2')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT x'0032', CONCAT(x'0032') LIMIT 0;
+x'0032'	CONCAT(x'0032')
+CREATE TABLE t1 AS SELECT x'0032', CONCAT(x'0032');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `x'0032'` varbinary(2) NOT NULL,
+  `CONCAT(x'0032')` varbinary(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject(x'0032');
+2	CONCAT('\x002')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `2` varchar(2) NOT NULL,
+  `CONCAT('\x002')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT x'3200', CONCAT(x'3200') LIMIT 0;
+x'3200'	CONCAT(x'3200')
+CREATE TABLE t1 AS SELECT x'3200', CONCAT(x'3200');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `x'3200'` varbinary(2) NOT NULL,
+  `CONCAT(x'3200')` varbinary(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject(x'3200');
+2\x00	CONCAT('2\x00')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `2\x00` varchar(2) NOT NULL,
+  `CONCAT('2\x00')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT '0\a', CONCAT('0\a') LIMIT 0;
+0a	CONCAT('0\a')
+CREATE TABLE t1 AS SELECT '0\a', CONCAT('0\a');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `0a` varchar(2) NOT NULL,
+  `CONCAT('0\a')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject('0\a');
+0a	CONCAT('0a')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `0a` varchar(2) NOT NULL,
+  `CONCAT('0a')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT 'a\0', CONCAT('a\0') LIMIT 0;
+a\x00	CONCAT('a\0')
+CREATE TABLE t1 AS SELECT 'a\0', CONCAT('a\0');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a\x00` varchar(2) NOT NULL,
+  `CONCAT('a\0')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject('a\0');
+a\x00	CONCAT('a\x00')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a\x00` varchar(2) NOT NULL,
+  `CONCAT('a\x00')` varchar(2) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT 'a\0b', CONCAT('a\0b') LIMIT 0;
+a\x00b	CONCAT('a\0b')
+CREATE TABLE t1 AS SELECT 'a\0b', CONCAT('a\0b');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a\x00b` varchar(3) NOT NULL,
+  `CONCAT('a\0b')` varchar(3) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CALL test_inject('a\0b');
+a\x00b	CONCAT('a\x00b')
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a\x00b` varchar(3) NOT NULL,
+  `CONCAT('a\x00b')` varchar(3) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP PROCEDURE test_inject;

mysql-test/main/ctype_big5.result

@@ -4710,7 +4710,7 @@ SELECT @@character_set_client, @@character_set_connection, @@character_set_resul
 @@character_set_client	@@character_set_connection	@@character_set_results
 binary	big5	binary
 SELECT HEX('\['), HEX('\\[');
-HEX('\[')	HEX('\\[')
+HEX('\xE0\[')	HEX('\\xE0\[')
 E05B	E05B
 CREATE TABLE t1 AS SELECT REPEAT(' ', 10) AS a LIMIT 0;
 SHOW CREATE TABLE t1;

mysql-test/main/ctype_cp932_binlog_stm.result

@@ -20418,7 +20418,7 @@ SELECT @@character_set_client, @@character_set_connection, @@character_set_resul
 @@character_set_client	@@character_set_connection	@@character_set_results
 binary	cp932	binary
 SELECT HEX('à\['), HEX('\à\[');
-HEX('à\[')	HEX('\à\[')
+HEX('\xE0\[')	HEX('\\xE0\[')
 E05B	E05B
 CREATE TABLE t1 AS SELECT REPEAT(' ', 10) AS a LIMIT 0;
 SHOW CREATE TABLE t1;

mysql-test/main/ctype_gbk.result

@@ -5054,7 +5054,7 @@ SELECT @@character_set_client, @@character_set_connection, @@character_set_resul
 @@character_set_client	@@character_set_connection	@@character_set_results
 binary	gbk	binary
 SELECT HEX('\['), HEX('\\[');
-HEX('\[')	HEX('\\[')
+HEX('\xE0\[')	HEX('\\xE0\[')
 E05B	E05B
 CREATE TABLE t1 AS SELECT REPEAT(' ', 10) AS a LIMIT 0;
 SHOW CREATE TABLE t1;

mysql-test/main/ctype_latin1.result

@@ -7963,37 +7963,37 @@ SELECT '
 ?
 ?
 SELECT HEX('');
-HEX('')
+HEX('\xC2')
 3F
 SELECT HEX(CAST('' AS CHAR CHARACTER SET utf8));
-HEX(CAST('' AS CHAR CHARACTER SET utf8))
+HEX(CAST('\xC2' AS CHAR CHARACTER SET utf8))
 3F
 SELECT HEX(CAST('' AS CHAR CHARACTER SET latin1));
-HEX(CAST('' AS CHAR CHARACTER SET latin1))
+HEX(CAST('\xC2' AS CHAR CHARACTER SET latin1))
 3F
 SELECT HEX(CONVERT('' USING utf8));
-HEX(CONVERT('' USING utf8))
+HEX(CONVERT('\xC2' USING utf8))
 3F
 SELECT HEX(CONVERT('' USING latin1));
-HEX(CONVERT('' USING latin1))
+HEX(CONVERT('\xC2' USING latin1))
 3F
 SELECT 'x';
 ?x
 ?x
 SELECT HEX('x');
-HEX('x')
+HEX('\xC2x')
 3F78
 SELECT HEX(CAST('x' AS CHAR CHARACTER SET utf8));
-HEX(CAST('x' AS CHAR CHARACTER SET utf8))
+HEX(CAST('\xC2x' AS CHAR CHARACTER SET utf8))
 3F78
 SELECT HEX(CAST('x' AS CHAR CHARACTER SET latin1));
-HEX(CAST('x' AS CHAR CHARACTER SET latin1))
+HEX(CAST('\xC2x' AS CHAR CHARACTER SET latin1))
 3F78
 SELECT HEX(CONVERT('x' USING utf8));
-HEX(CONVERT('x' USING utf8))
+HEX(CONVERT('\xC2x' USING utf8))
 3F78
 SELECT HEX(CONVERT('x' USING latin1));
-HEX(CONVERT('x' USING latin1))
+HEX(CONVERT('\xC2x' USING latin1))
 3F78
 SET NAMES utf8;
 CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1);

mysql-test/main/ctype_sjis.result

@@ -18682,7 +18682,7 @@ SELECT @@character_set_client, @@character_set_connection, @@character_set_resul
 @@character_set_client	@@character_set_connection	@@character_set_results
 binary	sjis	binary
 SELECT HEX('\['), HEX('\\[');
-HEX('\[')	HEX('\\[')
+HEX('\xE0\[')	HEX('\\xE0\[')
 E05B	E05B
 CREATE TABLE t1 AS SELECT REPEAT(' ', 10) AS a LIMIT 0;
 SHOW CREATE TABLE t1;

mysql-test/main/ctype_utf8.result

@@ -67,13 +67,13 @@ select _utf8 0xD0B0D0B1D0B2 like concat(_utf8'%',_utf8 0xD0B1,_utf8 '%');
 _utf8 0xD0B0D0B1D0B2 like concat(_utf8'%',_utf8 0xD0B1,_utf8 '%')
 1
 select convert(_latin1'Gnter Andr' using utf8) like CONVERT(_latin1'GNTER%' USING utf8);
-convert(_latin1'Gnter Andr' using utf8) like CONVERT(_latin1'GNTER%' USING utf8)
+convert(_latin1'G\xFCnter Andr\xE9' using utf8) like CONVERT(_latin1'G\xDCNTER%' USING utf8)
 1
 select CONVERT(_koi8r'' USING utf8) LIKE CONVERT(_koi8r'' USING utf8);
-CONVERT(_koi8r'' USING utf8) LIKE CONVERT(_koi8r'' USING utf8)
+CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8) LIKE CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8)
 1
 select CONVERT(_koi8r'' USING utf8) LIKE CONVERT(_koi8r'' USING utf8);
-CONVERT(_koi8r'' USING utf8) LIKE CONVERT(_koi8r'' USING utf8)
+CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8) LIKE CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8)
 1
 SELECT 'a' = 'a ';
 'a' = 'a '
@@ -1295,7 +1295,7 @@ concat(concat(_latin1'->',f1),_latin1'<-')
 -><-
 drop table t1;
 select convert(_koi8r'' using utf8) < convert(_koi8r'' using utf8);
-convert(_koi8r'' using utf8) < convert(_koi8r'' using utf8)
+convert(_koi8r'\xC9' using utf8) < convert(_koi8r'\xCA' using utf8)
 1
 set names latin1;
 create table t1 (a varchar(10)) character set utf8;

mysql-test/main/ctype_utf8mb4.result

@@ -67,13 +67,13 @@ select _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4
 _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4 '%')
 1
 select convert(_latin1'Gnter Andr' using utf8mb4) like CONVERT(_latin1'GNTER%' USING utf8mb4);
-convert(_latin1'G?nter Andr?' using utf8mb4) like CONVERT(_latin1'G?NTER%' USING utf8mb4)
+convert(_latin1'G\xFCnter Andr\xE9' using utf8mb4) like CONVERT(_latin1'G\xDCNTER%' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4) LIKE CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4) LIKE CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4)
 1
 SELECT 'a' = 'a ';
 'a' = 'a '
@@ -1316,7 +1316,7 @@ concat(concat(_latin1'->',f1),_latin1'<-')
 -><-
 drop table t1;
 select convert(_koi8r'' using utf8mb4) < convert(_koi8r'' using utf8mb4);
-convert(_koi8r'?' using utf8mb4) < convert(_koi8r'?' using utf8mb4)
+convert(_koi8r'\xC9' using utf8mb4) < convert(_koi8r'\xCA' using utf8mb4)
 1
 set names latin1;
 create table t1 (a varchar(10)) character set utf8mb4;

mysql-test/main/ctype_utf8mb4_heap.result

@@ -67,13 +67,13 @@ select _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4
 _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4 '%')
 1
 select convert(_latin1'Gnter Andr' using utf8mb4) like CONVERT(_latin1'GNTER%' USING utf8mb4);
-convert(_latin1'G?nter Andr?' using utf8mb4) like CONVERT(_latin1'G?NTER%' USING utf8mb4)
+convert(_latin1'G\xFCnter Andr\xE9' using utf8mb4) like CONVERT(_latin1'G\xDCNTER%' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4) LIKE CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4) LIKE CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4)
 1
 SELECT 'a' = 'a ';
 'a' = 'a '
@@ -1215,7 +1215,7 @@ concat(concat(_latin1'->',f1),_latin1'<-')
 -><-
 drop table t1;
 select convert(_koi8r'' using utf8mb4) < convert(_koi8r'' using utf8mb4);
-convert(_koi8r'?' using utf8mb4) < convert(_koi8r'?' using utf8mb4)
+convert(_koi8r'\xC9' using utf8mb4) < convert(_koi8r'\xCA' using utf8mb4)
 1
 set names latin1;
 create table t1 (a varchar(10)) character set utf8mb4 engine heap;

mysql-test/main/ctype_utf8mb4_innodb.result

@@ -67,13 +67,13 @@ select _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4
 _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4 '%')
 1
 select convert(_latin1'Gnter Andr' using utf8mb4) like CONVERT(_latin1'GNTER%' USING utf8mb4);
-convert(_latin1'G?nter Andr?' using utf8mb4) like CONVERT(_latin1'G?NTER%' USING utf8mb4)
+convert(_latin1'G\xFCnter Andr\xE9' using utf8mb4) like CONVERT(_latin1'G\xDCNTER%' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4) LIKE CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4) LIKE CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4)
 1
 SELECT 'a' = 'a ';
 'a' = 'a '
@@ -1278,7 +1278,7 @@ concat(concat(_latin1'->',f1),_latin1'<-')
 -><-
 drop table t1;
 select convert(_koi8r'' using utf8mb4) < convert(_koi8r'' using utf8mb4);
-convert(_koi8r'?' using utf8mb4) < convert(_koi8r'?' using utf8mb4)
+convert(_koi8r'\xC9' using utf8mb4) < convert(_koi8r'\xCA' using utf8mb4)
 1
 set names latin1;
 create table t1 (a varchar(10)) character set utf8mb4 engine InnoDB;

mysql-test/main/ctype_utf8mb4_myisam.result

@@ -67,13 +67,13 @@ select _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4
 _utf8mb4 0xD0B0D0B1D0B2 like concat(_utf8mb4'%',_utf8mb4 0xD0B1,_utf8mb4 '%')
 1
 select convert(_latin1'Gnter Andr' using utf8mb4) like CONVERT(_latin1'GNTER%' USING utf8mb4);
-convert(_latin1'G?nter Andr?' using utf8mb4) like CONVERT(_latin1'G?NTER%' USING utf8mb4)
+convert(_latin1'G\xFCnter Andr\xE9' using utf8mb4) like CONVERT(_latin1'G\xDCNTER%' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4) LIKE CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4)
 1
 select CONVERT(_koi8r'' USING utf8mb4) LIKE CONVERT(_koi8r'' USING utf8mb4);
-CONVERT(_koi8r'????' USING utf8mb4) LIKE CONVERT(_koi8r'????' USING utf8mb4)
+CONVERT(_koi8r'\xF7\xE1\xF3\xF1' USING utf8mb4) LIKE CONVERT(_koi8r'\xD7\xC1\xD3\xD1' USING utf8mb4)
 1
 SELECT 'a' = 'a ';
 'a' = 'a '
@@ -1281,7 +1281,7 @@ concat(concat(_latin1'->',f1),_latin1'<-')
 -><-
 drop table t1;
 select convert(_koi8r'' using utf8mb4) < convert(_koi8r'' using utf8mb4);
-convert(_koi8r'?' using utf8mb4) < convert(_koi8r'?' using utf8mb4)
+convert(_koi8r'\xC9' using utf8mb4) < convert(_koi8r'\xCA' using utf8mb4)
 1
 set names latin1;
 create table t1 (a varchar(10)) character set utf8mb4 engine MyISAM;

mysql-test/main/plugin.result

@@ -320,7 +320,7 @@ select plugin_name from information_schema.plugins where plugin_library like 'ha
 plugin_name
 set names utf8;
 select convert('admin𝌆' using utf8);
-convert('admin𝌆' using utf8)
+convert('admin\xF0\x9D\x8C\x86' using utf8)
 admin????
 Warnings:
 Warning	1300	Invalid utf8 character string: '\xF0\x9D\x8C\x86'

sql/item.cc

@@ -1217,6 +1217,80 @@ bool Item::check_type_scalar(const char *opname) const
 }
 
 
+extern "C" {
+
+/*
+  All values greater than MY_NAME_BINARY_VALUE are
+  interpreted as binary bytes.
+  The exact constant value does not matter,
+  but it must be greater than 0x10FFFF,
+  which is the maximum possible character in Unicode.
+*/
+#define MY_NAME_BINARY_VALUE 0x200000
+
+/*
+  Print all binary bytes as well as zero character U+0000 in hex notation.
+  Print other characters normally.
+*/
+static int
+my_wc_mb_item_name(CHARSET_INFO *cs, my_wc_t wc, uchar *str, uchar *end)
+{
+  if (wc == 0 || wc >= MY_NAME_BINARY_VALUE)
+  {
+    if (str + 4 >= end)
+      return MY_CS_TOOSMALL3;
+    str[0]= '\\';
+    str[1]= 'x';
+    str[2]= _dig_vec_upper[(uchar) (wc >> 4)];
+    str[3]= _dig_vec_upper[(uchar) wc & 0x0F];
+    return 4;
+  }
+  return my_charset_utf8_handler.wc_mb(cs, wc, str, end);
+}
+
+
+/*
+  Scan characters and mark all illegal sequences as binary byte values,
+  to have my_wc_mb_utf8_escape_name() print them using HEX notation.
+*/
+static int
+my_mb_wc_item_name(CHARSET_INFO *cs, my_wc_t *pwc,
+                   const uchar *str, const uchar *end)
+{
+  int rc= cs->cset->mb_wc(cs, pwc, str, end);
+  if (rc == MY_CS_ILSEQ)
+  {
+    *pwc= MY_NAME_BINARY_VALUE + *str;
+    return 1;
+  }
+  return rc;
+}
+
+}
+
+
+static LEX_CSTRING
+make_name(THD *thd,
+          const char *str, size_t length, CHARSET_INFO *cs,
+          size_t max_octet_length)
+{
+  uint errors;
+  size_t dst_nbytes= length * system_charset_info->mbmaxlen;
+  set_if_smaller(dst_nbytes, max_octet_length);
+  char *dst= (char*) thd->alloc(dst_nbytes + 1);
+  if (!dst)
+    return null_clex_str;
+  uint32 cnv_length= my_convert_using_func(dst, dst_nbytes, system_charset_info,
+                                           my_wc_mb_item_name,
+                                           str, length,
+                                           cs == &my_charset_bin ?
+                                             system_charset_info : cs,
+                                           my_mb_wc_item_name, &errors);
+  dst[cnv_length]= '\0';
+  return Lex_cstring(dst, cnv_length);
+}
+
+
 void Item::set_name(THD *thd, const char *str, size_t length, CHARSET_INFO *cs)
 {
   if (!length)
@@ -1267,32 +1341,14 @@ void Item::set_name(THD *thd, const char *str, size_t length, CHARSET_INFO *cs)
                           ER_REMOVED_SPACES, ER_THD(thd, ER_REMOVED_SPACES),
                           buff);
   }
-  if (!my_charset_same(cs, system_charset_info))
-  {
-    size_t res_length;
-    name.str= sql_strmake_with_convert(thd, str, length, cs,
-                                       MAX_ALIAS_NAME, system_charset_info,
-                                       &res_length);
-    name.length= res_length;
-  }
-  else
-    name.str= thd->strmake(str, (name.length= MY_MIN(length,MAX_ALIAS_NAME)));
+  name= make_name(thd, str, length, cs, MAX_ALIAS_NAME - 1);
 }
 
 
 void Item::set_name_no_truncate(THD *thd, const char *str, uint length,
                                 CHARSET_INFO *cs)
 {
-  if (!my_charset_same(cs, system_charset_info))
-  {
-    size_t res_length;
-    name.str= sql_strmake_with_convert(thd, str, length, cs,
-                                       UINT_MAX, system_charset_info,
-                                       &res_length);
-    name.length= res_length;
-  }
-  else
-    name.str= thd->strmake(str, (name.length= length));
+  name= make_name(thd, str, length, cs, UINT_MAX - 1);
 }