Bug#54916 GROUP_CONCAT + IFNULL truncates output

Problem: a few functions did not calculate their max_length correctly.
This is an after-fix for WL#2649 Number-to-string conversions".

Fix: changing the buggy functions to calculate max_length
using fix_char_length() introduced in WL#2649,
instead of setting max_length directly

  mysql-test/include/ctype_numconv.inc
     Adding new tests

  mysql-test/r/ctype_binary.result
     Adding new tests

  mysql-test/r/ctype_cp1251.result
     Adding new tests

  mysql-test/r/ctype_latin1.result
     Adding new tests

  mysql-test/r/ctype_ucs.result
     Adding new tests

  mysql-test/r/ctype_utf8.result
     Adding new tests

  mysql-test/t/ctype_utf8.test
    Including ctype_numconv

  sql/item.h
    - Introducing new method fix_char_length_ulonglong(),
    for the cases when length is potentially greater
    than UINT_MAX32. This method removes a few
    instances of duplicate code, e.g. in item_strfunc.cc.
    - Setting collation in Item_copy properly. This change
    fixes wrong metadata on client side in some cases, when
    "binary" instead of the real character set was reported.

  sql/item_cmpfunc.cc
    - Using fix_char_length() and max_char_length() methods,
    instead of direct access to max_length, to calculate
    item length properly.
    - Moving count_only_length() in COALESCE after
    agg_arg_charsets_for_string_result(). The old
    order was incorrect and led to wrong length
    calucation in case of multi-byte character sets.
    
  sql/item_func.cc
    Fixing that count_only_length() didn't work
    properly for multi-byte character sets.
    Using fix_char_length() and max_char_length()
    instead of direct access to max_length.

  sql/item_strfunc.cc
    - Using fix_char_length(), fix_char_length_ulonglong(),
    max_char_length() instead of direct access to max_length.
    - Removing wierd condition: "if (collation.collation->mbmaxlen > 0)",
    which is never FALSE.

mysql-test/include/ctype_numconv.inc

@@ -1625,6 +1625,108 @@ SET @x=aswkt(point(1,2));
 SELECT charset(@x), collation(@x);
 
 
+--echo #
+--echo # Bug#54916 GROUP_CONCAT + IFNULL truncates output
+--echo #
+SELECT @@collation_connection;
+# ENGINE=MYISAM is very important to make sure "SYSTEM" join type
+# is in use, which will create instances of Item_copy.
+CREATE TABLE t1 (a MEDIUMINT NULL) ENGINE=MYISAM;
+INSERT INTO t1 VALUES (1234567);
+SELECT GROUP_CONCAT(IFNULL(a,'')) FROM t1;
+SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
+if (`SELECT @@character_set_connection != 'ucs2'`)
+{
+  # Temporarily disable for ucs2
+  # For details, see Bug#55744 GROUP_CONCAT + CASE + ucs return garbage
+  SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
+}
+--enable_metadata
+SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
+--disable_metadata
+--echo # All columns must be VARCHAR(9) with the same length:
+--disable_warnings
+CREATE TABLE t2 AS
+SELECT
+  CONCAT(a),
+  IFNULL(a,''),
+  IF(a,a,''),
+  CASE WHEN a THEN a ELSE '' END,
+  COALESCE(a,'')
+FROM t1;
+--enable_warnings
+# The above query is expected to send a warning
+# in case of ucs2 character set, until Bug#55744 is fixed.
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT CONCAT_WS(1,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT INSERT(1133,3,0,22) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT LCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT UCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT REPEAT(1,2) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT LEFT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT RIGHT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT LTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT RTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT ELT(1,111,222,333) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT REPLACE(111,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT SUBSTRING_INDEX(111,111,1) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT MAKE_SET(111,222,3) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT SOUNDEX(1) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 AS SELECT EXPORT_SET(1,'Y','N','',8);
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+DROP TABLE t1;
+
+--echo #
+--echo # End of Bug#54916
+--echo #
+
+
 --echo #
 --echo # Bug#52159 returning time type from function and empty left join causes debug assertion
 --echo #

mysql-test/r/case.result

@@ -160,6 +160,8 @@ t1	CREATE TABLE `t1` (
   `COALESCE('a' COLLATE latin1_bin,'b')` varchar(1) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL DEFAULT ''
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
+CREATE TABLE t1 SELECT IFNULL('a' COLLATE latin1_swedish_ci, 'b' COLLATE latin1_bin);
+ERROR HY000: Illegal mix of collations (latin1_swedish_ci,EXPLICIT) and (latin1_bin,EXPLICIT) for operation 'ifnull'
 SELECT 'case+union+test'
 UNION 
 SELECT CASE LOWER('1') WHEN LOWER('2') THEN 'BUG' ELSE 'nobug' END;

mysql-test/r/ctype_binary.result

@@ -2598,6 +2598,156 @@ SELECT charset(@x), collation(@x);
 charset(@x)	collation(@x)
 binary	binary
 #
+# Bug#54916 GROUP_CONCAT + IFNULL truncates output
+#
+SELECT @@collation_connection;
+@@collation_connection
+binary
+CREATE TABLE t1 (a MEDIUMINT NULL) ENGINE=MYISAM;
+INSERT INTO t1 VALUES (1234567);
+SELECT GROUP_CONCAT(IFNULL(a,'')) FROM t1;
+GROUP_CONCAT(IFNULL(a,''))
+1234567
+SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
+GROUP_CONCAT(IF(a,a,''))
+1234567
+SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
+GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END)
+1234567
+SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					COALESCE(a,'')	253	9	7	Y	128	31	63
+COALESCE(a,'')
+1234567
+# All columns must be VARCHAR(9) with the same length:
+CREATE TABLE t2 AS
+SELECT
+CONCAT(a),
+IFNULL(a,''),
+IF(a,a,''),
+CASE WHEN a THEN a ELSE '' END,
+COALESCE(a,'')
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT(a)` varbinary(9) DEFAULT NULL,
+  `IFNULL(a,'')` varbinary(9) NOT NULL DEFAULT '',
+  `IF(a,a,'')` varbinary(9) DEFAULT NULL,
+  `CASE WHEN a THEN a ELSE '' END` varbinary(9) DEFAULT NULL,
+  `COALESCE(a,'')` varbinary(9) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT CONCAT_WS(1,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT_WS(1,2,3)` varbinary(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT INSERT(1133,3,0,22) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `INSERT(1133,3,0,22)` varbinary(6) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LCASE(a)` varbinary(9) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT UCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `UCASE(a)` varbinary(9) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPEAT(1,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPEAT(1,2)` varbinary(2) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LEFT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LEFT(123,2)` varbinary(2) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RIGHT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RIGHT(123,2)` varbinary(2) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LTRIM(123)` varbinary(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RTRIM(123)` varbinary(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT ELT(1,111,222,333) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `ELT(1,111,222,333)` varbinary(3) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPLACE(111,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPLACE(111,2,3)` varbinary(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SUBSTRING_INDEX(111,111,1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SUBSTRING_INDEX(111,111,1)` varbinary(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT MAKE_SET(111,222,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `MAKE_SET(111,222,3)` varbinary(5) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SOUNDEX(1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SOUNDEX(1)` varbinary(4) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT EXPORT_SET(1,'Y','N','',8);
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `EXPORT_SET(1,'Y','N','',8)` varbinary(64) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+#
+# End of Bug#54916
+#
+#
 # Bug#52159 returning time type from function and empty left join causes debug assertion
 #
 CREATE FUNCTION f1() RETURNS TIME RETURN 1;

mysql-test/r/ctype_cp1251.result

@@ -2680,6 +2680,156 @@ SELECT charset(@x), collation(@x);
 charset(@x)	collation(@x)
 cp1251	cp1251_general_ci
 #
+# Bug#54916 GROUP_CONCAT + IFNULL truncates output
+#
+SELECT @@collation_connection;
+@@collation_connection
+cp1251_general_ci
+CREATE TABLE t1 (a MEDIUMINT NULL) ENGINE=MYISAM;
+INSERT INTO t1 VALUES (1234567);
+SELECT GROUP_CONCAT(IFNULL(a,'')) FROM t1;
+GROUP_CONCAT(IFNULL(a,''))
+1234567
+SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
+GROUP_CONCAT(IF(a,a,''))
+1234567
+SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
+GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END)
+1234567
+SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					COALESCE(a,'')	253	9	7	Y	0	31	51
+COALESCE(a,'')
+1234567
+# All columns must be VARCHAR(9) with the same length:
+CREATE TABLE t2 AS
+SELECT
+CONCAT(a),
+IFNULL(a,''),
+IF(a,a,''),
+CASE WHEN a THEN a ELSE '' END,
+COALESCE(a,'')
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT(a)` varchar(9) CHARACTER SET cp1251 DEFAULT NULL,
+  `IFNULL(a,'')` varchar(9) CHARACTER SET cp1251 NOT NULL DEFAULT '',
+  `IF(a,a,'')` varchar(9) CHARACTER SET cp1251 DEFAULT NULL,
+  `CASE WHEN a THEN a ELSE '' END` varchar(9) CHARACTER SET cp1251 DEFAULT NULL,
+  `COALESCE(a,'')` varchar(9) CHARACTER SET cp1251 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT CONCAT_WS(1,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT_WS(1,2,3)` varchar(3) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT INSERT(1133,3,0,22) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `INSERT(1133,3,0,22)` varchar(6) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LCASE(a)` varchar(9) CHARACTER SET cp1251 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT UCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `UCASE(a)` varchar(9) CHARACTER SET cp1251 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPEAT(1,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPEAT(1,2)` varchar(2) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LEFT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LEFT(123,2)` varchar(2) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RIGHT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RIGHT(123,2)` varchar(2) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LTRIM(123)` varchar(3) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RTRIM(123)` varchar(3) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT ELT(1,111,222,333) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `ELT(1,111,222,333)` varchar(3) CHARACTER SET cp1251 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPLACE(111,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPLACE(111,2,3)` varchar(3) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SUBSTRING_INDEX(111,111,1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SUBSTRING_INDEX(111,111,1)` varchar(3) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT MAKE_SET(111,222,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `MAKE_SET(111,222,3)` varchar(5) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SOUNDEX(1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SOUNDEX(1)` varchar(4) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT EXPORT_SET(1,'Y','N','',8);
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `EXPORT_SET(1,'Y','N','',8)` varchar(64) CHARACTER SET cp1251 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+#
+# End of Bug#54916
+#
+#
 # Bug#52159 returning time type from function and empty left join causes debug assertion
 #
 CREATE FUNCTION f1() RETURNS TIME RETURN 1;

mysql-test/r/ctype_latin1.result

@@ -3008,6 +3008,156 @@ SELECT charset(@x), collation(@x);
 charset(@x)	collation(@x)
 latin1	latin1_swedish_ci
 #
+# Bug#54916 GROUP_CONCAT + IFNULL truncates output
+#
+SELECT @@collation_connection;
+@@collation_connection
+latin1_swedish_ci
+CREATE TABLE t1 (a MEDIUMINT NULL) ENGINE=MYISAM;
+INSERT INTO t1 VALUES (1234567);
+SELECT GROUP_CONCAT(IFNULL(a,'')) FROM t1;
+GROUP_CONCAT(IFNULL(a,''))
+1234567
+SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
+GROUP_CONCAT(IF(a,a,''))
+1234567
+SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
+GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END)
+1234567
+SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					COALESCE(a,'')	253	9	7	Y	0	31	8
+COALESCE(a,'')
+1234567
+# All columns must be VARCHAR(9) with the same length:
+CREATE TABLE t2 AS
+SELECT
+CONCAT(a),
+IFNULL(a,''),
+IF(a,a,''),
+CASE WHEN a THEN a ELSE '' END,
+COALESCE(a,'')
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT(a)` varchar(9) DEFAULT NULL,
+  `IFNULL(a,'')` varchar(9) NOT NULL DEFAULT '',
+  `IF(a,a,'')` varchar(9) DEFAULT NULL,
+  `CASE WHEN a THEN a ELSE '' END` varchar(9) DEFAULT NULL,
+  `COALESCE(a,'')` varchar(9) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT CONCAT_WS(1,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT_WS(1,2,3)` varchar(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT INSERT(1133,3,0,22) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `INSERT(1133,3,0,22)` varchar(6) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LCASE(a)` varchar(9) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT UCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `UCASE(a)` varchar(9) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPEAT(1,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPEAT(1,2)` varchar(2) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LEFT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LEFT(123,2)` varchar(2) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RIGHT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RIGHT(123,2)` varchar(2) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LTRIM(123)` varchar(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RTRIM(123)` varchar(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT ELT(1,111,222,333) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `ELT(1,111,222,333)` varchar(3) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPLACE(111,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPLACE(111,2,3)` varchar(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SUBSTRING_INDEX(111,111,1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SUBSTRING_INDEX(111,111,1)` varchar(3) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT MAKE_SET(111,222,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `MAKE_SET(111,222,3)` varchar(5) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SOUNDEX(1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SOUNDEX(1)` varchar(4) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT EXPORT_SET(1,'Y','N','',8);
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `EXPORT_SET(1,'Y','N','',8)` varchar(64) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+#
+# End of Bug#54916
+#
+#
 # Bug#52159 returning time type from function and empty left join causes debug assertion
 #
 CREATE FUNCTION f1() RETURNS TIME RETURN 1;

mysql-test/r/ctype_ucs.result

@@ -3840,6 +3840,153 @@ SELECT charset(@x), collation(@x);
 charset(@x)	collation(@x)
 ucs2	ucs2_general_ci
 #
+# Bug#54916 GROUP_CONCAT + IFNULL truncates output
+#
+SELECT @@collation_connection;
+@@collation_connection
+ucs2_general_ci
+CREATE TABLE t1 (a MEDIUMINT NULL) ENGINE=MYISAM;
+INSERT INTO t1 VALUES (1234567);
+SELECT GROUP_CONCAT(IFNULL(a,'')) FROM t1;
+GROUP_CONCAT(IFNULL(a,''))
+1234567
+SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
+GROUP_CONCAT(IF(a,a,''))
+1234567
+SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					COALESCE(a,'')	253	9	7	Y	0	31	8
+COALESCE(a,'')
+1234567
+# All columns must be VARCHAR(9) with the same length:
+CREATE TABLE t2 AS
+SELECT
+CONCAT(a),
+IFNULL(a,''),
+IF(a,a,''),
+CASE WHEN a THEN a ELSE '' END,
+COALESCE(a,'')
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT(a)` varchar(9) CHARACTER SET ucs2 DEFAULT NULL,
+  `IFNULL(a,'')` varchar(9) CHARACTER SET ucs2 NOT NULL DEFAULT '',
+  `IF(a,a,'')` varchar(9) CHARACTER SET ucs2 DEFAULT NULL,
+  `CASE WHEN a THEN a ELSE '' END` varchar(9) CHARACTER SET ucs2 DEFAULT NULL,
+  `COALESCE(a,'')` varchar(9) CHARACTER SET ucs2 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT CONCAT_WS(1,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `CONCAT_WS(1,2,3)` varchar(3) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT INSERT(1133,3,0,22) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `INSERT(1133,3,0,22)` varchar(6) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LCASE(a)` varchar(9) CHARACTER SET ucs2 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT UCASE(a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `UCASE(a)` varchar(9) CHARACTER SET ucs2 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPEAT(1,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPEAT(1,2)` varchar(2) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LEFT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LEFT(123,2)` varchar(2) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RIGHT(123,2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RIGHT(123,2)` varchar(2) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT LTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `LTRIM(123)` varchar(3) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT RTRIM(123) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `RTRIM(123)` varchar(3) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT ELT(1,111,222,333) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `ELT(1,111,222,333)` varchar(3) CHARACTER SET ucs2 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT REPLACE(111,2,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `REPLACE(111,2,3)` varchar(3) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SUBSTRING_INDEX(111,111,1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SUBSTRING_INDEX(111,111,1)` varchar(3) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT MAKE_SET(111,222,3) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `MAKE_SET(111,222,3)` varchar(5) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT SOUNDEX(1) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `SOUNDEX(1)` varchar(4) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT EXPORT_SET(1,'Y','N','',8);
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `EXPORT_SET(1,'Y','N','',8)` varchar(64) CHARACTER SET ucs2 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+#
+# End of Bug#54916
+#
+#
 # Bug#52159 returning time type from function and empty left join causes debug assertion
 #
 CREATE FUNCTION f1() RETURNS TIME RETURN 1;

mysql-test/t/case.test

@@ -111,6 +111,9 @@ explain extended SELECT
 SHOW CREATE TABLE t1;
 DROP TABLE t1;
 
+--error 1267
+CREATE TABLE t1 SELECT IFNULL('a' COLLATE latin1_swedish_ci, 'b' COLLATE latin1_bin);
+
 # Test for BUG#10151
 SELECT 'case+union+test'
 UNION 

mysql-test/t/ctype_utf8.test

@@ -1505,6 +1505,11 @@ CREATE TABLE t2 AS SELECT CONCAT(s1) FROM t1;
 SHOW CREATE TABLE t2;
 DROP TABLE t1, t2;
 
+
+SET NAMES utf8;
+--source include/ctype_numconv.inc
+
+
 --echo #
 --echo # End of 5.5 tests
 --echo #

sql/item.h

@@ -547,7 +547,7 @@ public:
      @see Query_arena::free_list
    */
   Item *next;
-  uint32 max_length;
+  uint32 max_length;                    /* Maximum length, in bytes */
   uint name_length;                     /* Length of name */
   int8 marker;
   uint8 decimals;
@@ -1221,6 +1221,18 @@ public:
     max_length= char_to_byte_length_safe(max_char_length_arg,
                                          collation.collation->mbmaxlen);
   }
+  void fix_char_length_ulonglong(ulonglong max_char_length_arg)
+  {
+    ulonglong max_result_length= max_char_length_arg *
+                                 collation.collation->mbmaxlen;
+    if (max_result_length >= MAX_BLOB_WIDTH)
+    {
+      max_length= MAX_BLOB_WIDTH;
+      maybe_null= 1;
+    }
+    else
+      max_length= max_result_length;
+  }
   void fix_length_and_charset_datetime(uint32 max_char_length_arg)
   {
     collation.set(&my_charset_numeric, DERIVATION_NUMERIC, MY_REPERTOIRE_ASCII);
@@ -2825,6 +2837,7 @@ protected:
     cached_result_type= item->result_type();
     unsigned_flag= item->unsigned_flag;
     fixed= item->fixed;
+    collation.set(item->collation);
   }
 
 public:

sql/item_cmpfunc.cc

@@ -2374,6 +2374,7 @@ void Item_func_between::print(String *str, enum_query_type query_type)
 void
 Item_func_ifnull::fix_length_and_dec()
 {
+  uint32 char_length;
   agg_result_type(&hybrid_type, args, 2);
   maybe_null=args[1]->maybe_null;
   decimals= max(args[0]->decimals, args[1]->decimals);
@@ -2381,20 +2382,21 @@ Item_func_ifnull::fix_length_and_dec()
 
   if (hybrid_type == DECIMAL_RESULT || hybrid_type == INT_RESULT) 
   {
-    int len0= args[0]->max_length - args[0]->decimals
+    int len0= args[0]->max_char_length() - args[0]->decimals
       - (args[0]->unsigned_flag ? 0 : 1);
 
-    int len1= args[1]->max_length - args[1]->decimals
+    int len1= args[1]->max_char_length() - args[1]->decimals
       - (args[1]->unsigned_flag ? 0 : 1);
 
-    max_length= max(len0, len1) + decimals + (unsigned_flag ? 0 : 1);
+    char_length= max(len0, len1) + decimals + (unsigned_flag ? 0 : 1);
   }
   else
-    max_length= max(args[0]->max_length, args[1]->max_length);
+    char_length= max(args[0]->max_char_length(), args[1]->max_char_length());
 
   switch (hybrid_type) {
   case STRING_RESULT:
-    agg_arg_charsets_for_comparison(collation, args, arg_count);
+    if (agg_arg_charsets_for_comparison(collation, args, arg_count))
+      return;
     break;
   case DECIMAL_RESULT:
   case REAL_RESULT:
@@ -2406,6 +2408,7 @@ Item_func_ifnull::fix_length_and_dec()
   default:
     DBUG_ASSERT(0);
   }
+  fix_char_length(char_length);
   cached_field_type= agg_field_type(args, 2);
 }
 
@@ -2579,6 +2582,7 @@ Item_func_if::fix_length_and_dec()
     cached_field_type= agg_field_type(args + 1, 2);
   }
 
+  uint32 char_length;
   if ((cached_result_type == DECIMAL_RESULT )
       || (cached_result_type == INT_RESULT))
   {
@@ -2588,10 +2592,11 @@ Item_func_if::fix_length_and_dec()
     int len2= args[2]->max_length - args[2]->decimals
       - (args[2]->unsigned_flag ? 0 : 1);
 
-    max_length=max(len1, len2) + decimals + (unsigned_flag ? 0 : 1);
+    char_length= max(len1, len2) + decimals + (unsigned_flag ? 0 : 1);
   }
   else
-    max_length= max(args[1]->max_length, args[2]->max_length);
+    char_length= max(args[1]->max_char_length(), args[2]->max_char_length());
+  fix_char_length(char_length);
 }
 
 
@@ -2901,7 +2906,7 @@ bool Item_func_case::fix_fields(THD *thd, Item **ref)
 
 void Item_func_case::agg_str_lengths(Item* arg)
 {
-  set_if_bigger(max_length, arg->max_length);
+  fix_char_length(max(max_char_length(), arg->max_char_length()));
   set_if_bigger(decimals, arg->decimals);
   unsigned_flag= unsigned_flag && arg->unsigned_flag;
 }
@@ -3129,9 +3134,10 @@ void Item_func_coalesce::fix_length_and_dec()
   agg_result_type(&hybrid_type, args, arg_count);
   switch (hybrid_type) {
   case STRING_RESULT:
-    count_only_length();
     decimals= NOT_FIXED_DEC;
-    agg_arg_charsets_for_string_result(collation, args, arg_count);
+    if (agg_arg_charsets_for_string_result(collation, args, arg_count))
+      return;
+    count_only_length();
     break;
   case DECIMAL_RESULT:
     count_decimal_length();

sql/item_func.cc

@@ -564,8 +564,9 @@ void Item_func::count_decimal_length()
     set_if_smaller(unsigned_flag, args[i]->unsigned_flag);
   }
   int precision= min(max_int_part + decimals, DECIMAL_MAX_PRECISION);
-  max_length= my_decimal_precision_to_length_no_truncation(precision, decimals,
-                                                           unsigned_flag);
+  fix_char_length(my_decimal_precision_to_length_no_truncation(precision,
+                                                               decimals,
+                                                               unsigned_flag));
 }
 
 
@@ -575,13 +576,14 @@ void Item_func::count_decimal_length()
 
 void Item_func::count_only_length()
 {
-  max_length= 0;
+  uint32 char_length= 0;
   unsigned_flag= 0;
   for (uint i=0 ; i < arg_count ; i++)
   {
-    set_if_bigger(max_length, args[i]->max_length);
+    set_if_bigger(char_length, args[i]->max_char_length());
     set_if_bigger(unsigned_flag, args[i]->unsigned_flag);
   }
+  fix_char_length(char_length);
 }