bk commit into 4.1 tree (evgen:1.2386) BUG#12537

[eugene]

Below is the list of changes that have just been committed into a local
4.1 repository of evgen. When evgen 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
  1.2386 05/08/23 17:34:38 evgen@stripped +4 -0
  Fix bug #12537 UNION produces longtext instead of varchar
  
  Item::tmp_table_field_from_field_type() and create_tmp_field_from_item()
  was converting string field to blob depending on byte-wise length instead of
  character length, which results in converting valid varchar string with
  length == 86 to longtext.
  
  Made that functions above take into account max width of character when
  converting string fields to blobs.

  mysql-test/t/create.test
    1.57 05/08/23 17:34:08 evgen@stripped +9 -0
    Test case for bug #12537 UNION produces longtext instead of varchar

  mysql-test/r/create.result
    1.84 05/08/23 17:33:43 evgen@stripped +7 -0
    Test case for bug #12537 UNION produces longtext instead of varchar

  sql/sql_select.cc
    1.431 05/08/23 17:33:13 evgen@stripped +2 -1
    Fix bug #12537 UNION produces longtext instead of varchar
     create_tmp_field_from_item()now taking into account max char width when creating tmp
field for string fields.

  sql/item.cc
    1.217 05/08/23 17:31:22 evgen@stripped +4 -2
    Fix bug #12537 UNION produces longtext instead of varchar
    Item::tmp_table_field_from_field_type() now taking into account max char width when
creating tmp field for string fields.

# 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:	evgen
# Host:	moonbone.local
# Root:	/work/12537-bug-4.1-mysql

--- 1.216/sql/item.cc	2005-08-17 12:26:27 +04:00
+++ 1.217/sql/item.cc	2005-08-23 17:31:22 +04:00
@@ -2022,12 +2022,14 @@
   case MYSQL_TYPE_ENUM:
   case MYSQL_TYPE_SET:
   case MYSQL_TYPE_VAR_STRING:
-    if (max_length > 255)
+    if ((max_length > 255 && !collation.collation) ||
+        max_length/collation.collation->mbmaxlen > 255)
       break;					// If blob
     return new Field_varstring(max_length, maybe_null, name, table,
 			       collation.collation);
   case MYSQL_TYPE_STRING:
-    if (max_length > 255)			// If blob
+    if ((max_length > 255 && !collation.collation) ||
+        max_length/collation.collation->mbmaxlen > 255)		// If blob
       break;
     return new Field_string(max_length, maybe_null, name, table,
 			    collation.collation);

--- 1.430/sql/sql_select.cc	2005-08-16 08:26:07 +04:00
+++ 1.431/sql/sql_select.cc	2005-08-23 17:33:13 +04:00
@@ -4899,7 +4899,8 @@
 				   item->name, table, item->unsigned_flag);
     break;
   case STRING_RESULT:
-    if (item->max_length > 255)
+    if ((item->max_length > 255 && !item->collation.collation) ||
+        item->max_length/item->collation.collation->mbmaxlen > 255)
     {
       if (convert_blob_length)
         new_field= new Field_varstring(convert_blob_length, maybe_null,

--- 1.83/mysql-test/r/create.result	2005-07-22 07:08:45 +04:00
+++ 1.84/mysql-test/r/create.result	2005-08-23 17:33:43 +04:00
@@ -580,6 +580,13 @@
 create table t1(t1.name int);
 create table t2(test.t2.name int);
 drop table t1,t2;
+CREATE TABLE t1 (f1 VARCHAR(255) CHARACTER SET utf8);
+CREATE TABLE t2 AS SELECT LEFT(f1,86) AS f2 FROM t1 UNION SELECT LEFT(f1,86)
+AS f2 FROM t1;
+DESC t2;
+Field	Type	Null	Key	Default	Extra
+f2	varchar(86)	YES		NULL	
+DROP TABLE t1,t2;
 create database mysqltest;
 use mysqltest;
 drop database mysqltest;

--- 1.56/mysql-test/t/create.test	2005-07-28 04:21:39 +04:00
+++ 1.57/mysql-test/t/create.test	2005-08-23 17:34:08 +04:00
@@ -493,6 +493,15 @@
 drop table t1,t2;
 
 #
+# Bug #12537: UNION produces longtext instead of varchar
+#
+CREATE TABLE t1 (f1 VARCHAR(255) CHARACTER SET utf8);
+CREATE TABLE t2 AS SELECT LEFT(f1,86) AS f2 FROM t1 UNION SELECT LEFT(f1,86)
+AS f2 FROM t1;
+DESC t2;
+DROP TABLE t1,t2;
+
+#
 # Bug#11028: Crash on create table like
 #
 create database mysqltest;