bk commit into 5.0 tree (gluh:1.2152) BUG#19599

[gluh]

Below is the list of changes that have just been committed into a local
5.0 repository of gluh. When gluh 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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ChangeSet
  1.2152 06/05/29 14:31:13 gluh@stripped +3 -0
  Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
  do not use item buffer for result value if item is const

  sql/item_strfunc.cc
    1.267 06/05/29 14:29:39 gluh@stripped +5 -1
    Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
    do not use item buffer for result value if item is const

  mysql-test/t/information_schema.test
    1.81 06/05/29 14:29:39 gluh@stripped +10 -0
    Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
    test case

  mysql-test/r/information_schema.result
    1.106 06/05/29 14:29:39 gluh@stripped +9 -0
    Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
    test case

# 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:	gluh
# Host:	eagle.intranet.mysql.r18.ru
# Root:	/home/gluh/MySQL/Bugs/5.0.19599

--- 1.266/sql/item_strfunc.cc	Fri May 12 12:15:11 2006
+++ 1.267/sql/item_strfunc.cc	Mon May 29 14:29:39 2006
@@ -288,10 +288,12 @@ String *Item_func_concat::val_str(String
   DBUG_ASSERT(fixed == 1);
   String *res,*res2,*use_as_buff;
   uint i;
+  bool res_is_const= FALSE;
 
   null_value=0;
   if (!(res=args[0]->val_str(str)))
     goto null;
+  res_is_const= args[0]->const_item();
   use_as_buff= &tmp_value;
   for (i=1 ; i < arg_count ; i++)
   {
@@ -299,6 +301,7 @@ String *Item_func_concat::val_str(String
     {
       if (!(res=args[i]->val_str(str)))
 	goto null;
+      res_is_const= args[i]->const_item();
     }
     else
     {
@@ -315,7 +318,8 @@ String *Item_func_concat::val_str(String
 			    current_thd->variables.max_allowed_packet);
 	goto null;
       }
-      if (res->alloced_length() >= res->length()+res2->length())
+      if (res->alloced_length() >= res->length()+res2->length() &&
+          !res_is_const)
       {						// Use old buffer
 	res->append(*res2);
       }

--- 1.105/mysql-test/r/information_schema.result	Tue May 23 12:45:19 2006
+++ 1.106/mysql-test/r/information_schema.result	Mon May 29 14:29:39 2006
@@ -1121,3 +1121,12 @@ NULL	test	v2	select 1 AS `1`	NONE	NO	mys
 drop view v1, v2;
 drop table t1;
 drop user mysqltest_1@localhost;
+set @a:= '.';
+create table t1(f1 char(5));
+create table t2(f1 char(5));
+select concat(@a, table_name), @a, table_name
+from information_schema.tables where table_schema = 'test';
+concat(@a, table_name)	@a	table_name
+.t1	.	t1
+.t2	.	t2
+drop table t1,t2;

--- 1.80/mysql-test/t/information_schema.test	Tue May 23 20:05:32 2006
+++ 1.81/mysql-test/t/information_schema.test	Mon May 29 14:29:39 2006
@@ -838,3 +838,13 @@ connection default;
 drop view v1, v2;
 drop table t1;
 drop user mysqltest_1@localhost;
+
+#
+# Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
+#
+set @a:= '.';
+create table t1(f1 char(5));
+create table t2(f1 char(5));
+select concat(@a, table_name), @a, table_name
+from information_schema.tables where table_schema = 'test';
+drop table t1,t2;