- MDEV-6695 Bad column name for UCS2 string literals

  The Item_string constructors called set_name() on the source string,
  which was wrong because in case of UCS2/UTF16/UTF32 the source value
  might be a not well formed string (e.g. have incomplete leftmost character).
  Now set_name() is called on str_value after its copied 
  (with optionally left zero padding) from the source string.
- MDEV-6694 Illegal mix of collation with a PS parameter
  Item_param::convert_str_value() did not set repertoire.
  Introducing a new structure MY_STRING_METADATA to collect
  character length and repertoire of a string in a single loop,
  to avoid two separate loops. Adding a new class Item_basic_value::Metadata
  as a convenience wrapper around MY_STRING_METADATA, to reuse the
  code between Item_string and Item_param.

4 files changed, 55 insertions, 0 deletions

diff --git a/mysql-test/r/ctype_ucs.result b/mysql-test/r/ctype_ucs.result
index a98295c10ce..3cfc076b8a0 100644
--- a/mysql-test/r/ctype_ucs.result
+++ b/mysql-test/r/ctype_ucs.result
@@ -5333,5 +5333,12 @@ SELECT CONCAT(CONVERT('pi=' USING ucs2),PI()) AS PI;
 PI
 pi=3.141593
 #
+# MDEV-6695 Bad column name for UCS2 string literals
+#
+SET NAMES utf8, character_set_connection=ucs2;
+SELECT 'a','aa';
+a	aa
+a	aa
+#
 # End of 10.0 tests
 #
diff --git a/mysql-test/r/ctype_utf8.result b/mysql-test/r/ctype_utf8.result
index 8a3fcd9dc0d..767f0b04b98 100644
--- a/mysql-test/r/ctype_utf8.result
+++ b/mysql-test/r/ctype_utf8.result
@@ -6008,5 +6008,28 @@ CONCAT(a, IF(b>10, _utf8 X'61', _utf8 B'01100001'))
 aa
 DROP TABLE t1;
 #
+#  MDEV-6694 Illegal mix of collation with a PS parameter
+#
+SET NAMES utf8;
+CREATE TABLE t1 (a INT, b VARCHAR(10) CHARACTER SET latin1);
+INSERT INTO t1 VALUES (1,'a');
+SELECT CONCAT(b,IF(a,'b','b')) FROM t1;
+CONCAT(b,IF(a,'b','b'))
+ab
+PREPARE stmt FROM "SELECT CONCAT(b,IF(a,?,?)) FROM t1";
+SET @b='b';
+EXECUTE stmt USING @b,@b;
+CONCAT(b,IF(a,?,?))
+ab
+SET @b='';
+EXECUTE stmt USING @b,@b;
+CONCAT(b,IF(a,?,?))
+a
+SET @b='я';
+EXECUTE stmt USING @b,@b;
+ERROR HY000: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation 'concat'
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+#
 # End of 10.0 tests
 #
diff --git a/mysql-test/t/ctype_ucs.test b/mysql-test/t/ctype_ucs.test
index 94d79494502..d269fb35dfe 100644
--- a/mysql-test/t/ctype_ucs.test
+++ b/mysql-test/t/ctype_ucs.test
@@ -903,5 +903,12 @@ DROP TABLE t1;
 SELECT CONCAT(CONVERT('pi=' USING ucs2),PI()) AS PI;
 
 --echo #
+--echo # MDEV-6695 Bad column name for UCS2 string literals
+--echo #
+SET NAMES utf8, character_set_connection=ucs2;
+SELECT 'a','aa';
+
+
+--echo #
 --echo # End of 10.0 tests
 --echo #
diff --git a/mysql-test/t/ctype_utf8.test b/mysql-test/t/ctype_utf8.test
index 75630cf9cd5..eca1be2b4e7 100644
--- a/mysql-test/t/ctype_utf8.test
+++ b/mysql-test/t/ctype_utf8.test
@@ -1719,6 +1719,24 @@ SELECT CONCAT(a, IF(b>10, _utf8 X'61', _utf8 X'61')) FROM t1;
 SELECT CONCAT(a, IF(b>10, _utf8 X'61', _utf8 B'01100001')) FROM t1;
 DROP TABLE t1;
 
+--echo #
+--echo #  MDEV-6694 Illegal mix of collation with a PS parameter
+--echo #
+SET NAMES utf8;
+CREATE TABLE t1 (a INT, b VARCHAR(10) CHARACTER SET latin1);
+INSERT INTO t1 VALUES (1,'a');
+SELECT CONCAT(b,IF(a,'b','b')) FROM t1;
+PREPARE stmt FROM "SELECT CONCAT(b,IF(a,?,?)) FROM t1";
+SET @b='b';
+EXECUTE stmt USING @b,@b;
+SET @b='';
+EXECUTE stmt USING @b,@b;
+SET @b='я';
+--error ER_CANT_AGGREGATE_2COLLATIONS
+EXECUTE stmt USING @b,@b;
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+
 
 --echo #
 --echo # End of 10.0 tests