bzr commit into mysql-5.0-bugteam branch (ramil:2712) Bug#36772

[Ramil Kalimullin]

#At file:///home/ram/mysql/b36772.5.0-bugteam/

 2712 Ramil Kalimullin	2008-11-13
      Fix for bug#36772: When using UTF8, CONVERT with GROUP BY
      returns truncated results
      
      Problem: performig conversion from {INT, DECIMAL, REAL} to CHAR
      we incorrectly set its max length in some cases that may lead
      to truncated results returned.
      
      Fix: properly set CONVERT({INT, DECIMAL, REAL}, CHAR) result's
      max length.
modified:
  mysql-test/r/ctype_utf8.result
  mysql-test/t/ctype_utf8.test
  sql/item_timefunc.cc

per-file messages:
  mysql-test/r/ctype_utf8.result
    Fix for bug#36772: When using UTF8, CONVERT with GROUP BY
    returns truncated results
      - test result.
  mysql-test/t/ctype_utf8.test
    Fix for bug#36772: When using UTF8, CONVERT with GROUP BY
    returns truncated results
      - test case.
  sql/item_timefunc.cc
    Fix for bug#36772: When using UTF8, CONVERT with GROUP BY
    returns truncated results
      - calculating Item_char_typecast::max_length use initial
    argument's charset mbmaxlen instead of from_cs->mbmaxlen,
    as from_cs may differ in some case (see comment above).
=== modified file 'mysql-test/r/ctype_utf8.result'
--- a/mysql-test/r/ctype_utf8.result	2007-10-30 08:21:44 +0000
+++ b/mysql-test/r/ctype_utf8.result	2008-11-13 08:59:32 +0000
@@ -1813,3 +1813,35 @@ select hex(_utf8 B'001111111111');
 ERROR HY000: Invalid utf8 character string: 'FF'
 select (_utf8 X'616263FF');
 ERROR HY000: Invalid utf8 character string: 'FF'
+CREATE TABLE t1 (a INT NOT NULL, b INT NOT NULL);
+INSERT INTO t1 VALUES (70000, 1092), (70001, 1085), (70002, 1065);
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1 GROUP BY b;
+CONVERT(a, CHAR)	CONVERT(b, CHAR)
[phone]
[phone]
[phone]
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1;
+CONVERT(a, CHAR)	CONVERT(b, CHAR)
[phone]
[phone]
[phone]
+ALTER TABLE t1 ADD UNIQUE (b);
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1 GROUP BY b;
+CONVERT(a, CHAR)	CONVERT(b, CHAR)
[phone]
[phone]
[phone]
+DROP INDEX b ON t1;
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1 GROUP BY b;
+CONVERT(a, CHAR)	CONVERT(b, CHAR)
[phone]
[phone]
[phone]
+ALTER TABLE t1 ADD INDEX (b);
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) from t1 GROUP BY b;
+CONVERT(a, CHAR)	CONVERT(b, CHAR)
[phone]
[phone]
[phone]
+DROP TABLE t1;
+End of 5.0 tests

=== modified file 'mysql-test/t/ctype_utf8.test'
--- a/mysql-test/t/ctype_utf8.test	2007-10-30 08:21:44 +0000
+++ b/mysql-test/t/ctype_utf8.test	2008-11-13 08:59:32 +0000
@@ -1437,3 +1437,20 @@ select hex(_utf8 X'616263FF');
 select hex(_utf8 B'001111111111');
 --error ER_INVALID_CHARACTER_STRING
 select (_utf8 X'616263FF');
+
+#
+# Bug #36772: When using UTF8, CONVERT with GROUP BY returns truncated results
+#
+CREATE TABLE t1 (a INT NOT NULL, b INT NOT NULL);
+INSERT INTO t1 VALUES (70000, 1092), (70001, 1085), (70002, 1065);
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1 GROUP BY b;
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1;
+ALTER TABLE t1 ADD UNIQUE (b);
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1 GROUP BY b;
+DROP INDEX b ON t1;
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) FROM t1 GROUP BY b;
+ALTER TABLE t1 ADD INDEX (b);
+SELECT CONVERT(a, CHAR), CONVERT(b, CHAR) from t1 GROUP BY b;
+DROP TABLE t1;
+
+--echo End of 5.0 tests

=== modified file 'sql/item_timefunc.cc'
--- a/sql/item_timefunc.cc	2008-01-23 18:48:29 +0000
+++ b/sql/item_timefunc.cc	2008-11-13 08:59:32 +0000
@@ -2557,12 +2557,13 @@ void Item_char_typecast::fix_length_and_
            (cast_cs->mbminlen == 1 ? cast_cs : &my_charset_latin1) :
            args[0]->collation.collation;
   charset_conversion= (cast_cs->mbmaxlen > 1) ||
-                      !my_charset_same(from_cs, cast_cs) &&
-                      from_cs != &my_charset_bin &&
-                      cast_cs != &my_charset_bin;
+                      (!my_charset_same(from_cs, cast_cs) &&
+                       from_cs != &my_charset_bin &&
+                       cast_cs != &my_charset_bin);
   collation.set(cast_cs, DERIVATION_IMPLICIT);
-  char_length= (cast_length >= 0) ? cast_length : 
-	       args[0]->max_length/from_cs->mbmaxlen;
+  char_length= (cast_length >= 0) ?
+                 cast_length : 
+	         args[0]->max_length / args[0]->collation.collation->mbmaxlen;
   max_length= char_length * cast_cs->mbmaxlen;
 }