MySQL Bugs: #34052: Patch http://lists.mysql.com/commits/37203 for Bug#27959 needs better docs.

Bug #34052	Patch http://lists.mysql.com/commits/37203 for Bug#27959 needs better docs.
Submitted:	25 Jan 2008 10:09	Modified:	15 Jul 2008 18:10
Reporter:	Tonci Grgin
Status:	Closed
Category:	Connector/Net: Docs	Severity:	S2 (Serious)
Version:		OS:	Any
Assigned to:	MC Brown	Target Version:
Triage:	D4 (Minor) / R3 (Medium) / E3 (Medium)

Description:
Looking into patch source one can see a problem as reporter described in last comment in
Bug#27959: "GetValue() on a field tinyint(1) returning a Boolean is causing a bug in our
software where we expect an int object returned."

Part of patch:
         public IMySqlValue GetValueObject()
         {
-            return GetIMySqlValue(Type);
+            IMySqlValue v = GetIMySqlValue(Type);
+            if (v is MySqlByte && ColumnLength == 1)
+            {
+                MySqlByte b = (MySqlByte)v;
+                b.TreatAsBoolean = true;
+                v = b;
+            }
+            return v;
         }

How to repeat:
mysql> CREATE TABLE bug27959 (f_bool BOOLEAN);
Query OK, 0 rows affected (0.09 sec)

mysql> SHOW CREATE TABLE bug27959\G
*************************** 1. row ***************************
       Table: bug27959
Create Table: CREATE TABLE `bug27959` (
  `f_bool` tinyint(1) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

and

mysql> CREATE TABLE bug27959_1 (f_tint TINYINT(1));
Query OK, 0 rows affected (0.05 sec)

mysql> SHOW CREATE TABLE bug27959_1\G
*************************** 1. row ***************************
       Table: bug27959_1
Create Table: CREATE TABLE `bug27959_1` (
  `f_tint` tinyint(1) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

Suggested fix:
Please modify the patch and/or add a note to manual that TINYINT fields should be defined
at least as TINYINT(2) so not to be treated as BOOLEAN fields (explicitly).

After considering http://dev.mysql.com/doc/refman/5.0/en/numeric-type-overview.html I've
decided that it would be enough for MC to add link from c/NET pages to the above one
along with previously proposed text. Changing the synopsis.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/41806

Fixed in 5.1.5 and 5.2+

The .NET connector documentation has been updated to include the new 'Treat Tiny As
Boolean' connection string option.

An entry has also been added to the 5.1.5 and 5.2.0 changelogs:

Performing GetValue() on a field TINYINT(1) returned a BOOLEAN. While not a bug, this
caused problems in software that expected an INT to be returned. A new connection string
option Treat Tiny As Boolean has been added with a default value of true. If set to false
the provider will treat TINYINT(1) as INT.