bk commit into 4.1 tree (ramil:1.2540) BUG#20204

[ramil]

Below is the list of changes that have just been committed into a local
4.1 repository of ram. When ram does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2006-09-08 19:02:54+05:00, ramil@stripped +3 -0
  Fix for bug #20204: "order by" changes the results returned
  
  Item_substr's results are improperly stored in a temporary table due to
  wrongly calculated max_length value for multi-byte charsets if two
  arguments specified.

  mysql-test/r/ctype_utf8.result@stripped, 2006-09-08 19:02:49+05:00, ramil@stripped +12 -0
    Fix for bug #20204: "order by" changes the results returned
      - test result.

  mysql-test/t/ctype_utf8.test@stripped, 2006-09-08 19:02:49+05:00, ramil@stripped +12 -0
    Fix for bug #20204: "order by" changes the results returned
      - test case.

  sql/item_strfunc.cc@stripped, 2006-09-08 19:02:49+05:00, ramil@stripped +2 -1
    Fix for bug #20204: "order by" changes the results returned
      - always take into account current mbmaxlen value calculating max_length.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	ramil
# Host:	myoffice.izhnet.ru
# Root:	/usr/home/ram/work/bug20204/my41-bug20204

--- 1.246/sql/item_strfunc.cc	2006-09-08 19:03:01 +05:00
+++ 1.247/sql/item_strfunc.cc	2006-09-08 19:03:01 +05:00
@@ -1104,12 +1104,13 @@
   }
   if (arg_count == 3 && args[2]->const_item())
   {
-    int32 length= (int32) args[2]->val_int() * collation.collation->mbmaxlen;
+    int32 length= (int32) args[2]->val_int();
     if (length <= 0)
       max_length=0; /* purecov: inspected */
     else
       set_if_smaller(max_length,(uint) length);
   }
+  max_length*= collation.collation->mbmaxlen;
 }
 
 

--- 1.73/mysql-test/r/ctype_utf8.result	2006-09-08 19:03:01 +05:00
+++ 1.74/mysql-test/r/ctype_utf8.result	2006-09-08 19:03:01 +05:00
@@ -1293,3 +1293,15 @@
 42749	72	VOLNÝ ADSL
 44205	72	VOLNÝ ADSL
 DROP TABLE t1;
+create table t1(a char(10)) default charset utf8;
+insert into t1 values ('123'), ('456');
+explain
+select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	Y	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	SIMPLE	Z	ALL	NULL	NULL	NULL	NULL	2	Using where
+select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
+substr(Z.a,-1)	a
+3	123
+6	456
+drop table t1;

--- 1.75/mysql-test/t/ctype_utf8.test	2006-09-08 19:03:01 +05:00
+++ 1.76/mysql-test/t/ctype_utf8.test	2006-09-08 19:03:01 +05:00
@@ -1040,4 +1040,16 @@
 SELECT * FROM t1 WHERE tid=72 and val LIKE 'VOLNÝ ADSL'; 
 
 DROP TABLE t1;
+
+#
+# Bug #20204: substr(s, p) returns empty strings
+#
+
+create table t1(a char(10)) default charset utf8;
+insert into t1 values ('123'), ('456');
+explain
+  select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
+select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
+drop table t1;
+
 # End of 4.1 tests