Suddenly $dbh->{AutoCommit}=0 => 'Transactions not supported by database' - Christian Hammers - com.mysql.lists.perl

4 messages in com.mysql.lists.perlSuddenly $dbh->{AutoCommit}=0 => '...

From	Sent On	Attachments
Christian Hammers	23 Aug 2006 17:02
Benton, Kevin	24 Aug 2006 09:00
Christian Hammers	24 Aug 2006 09:29
Christian Hammers	25 Aug 2006 02:27

Subject:	Suddenly $dbh->{AutoCommit}=0 => 'Transactions not supported by database'
From:	Christian Hammers (ch...@debian.org)
Date:	08/25/2006 02:27:16 AM
List:	com.mysql.lists.perl

Hello

This might seem the cause of the recent buggy behaviour of DBD::mysql:

bye,

-christian-

On 2006-08-25 Niko Tyni wrote:

On Thu, Aug 24, 2006 at 02:02:43AM +0200, Christian Hammers wrote:

Some users of the Debian packages I create recently reported that after the upgrade from MySQL 5.0.22 to 5.0.24 Perl scripts that try to explicitly set $dbh->{AutoCommit} = 0; die with the error message: "Transactions not supported by database"

Hi,

this bug (#384047) is also at least #384221 (libdbd-mysql-perl) and #383700 (request-tracker3.4).

I believe the problem is an incompatible ABI change in libmysqlclient.15.so with version 5.0.24.

This addition in struct st_mysql_options:

--- mysql-dfsg-5.0-5.0.22/include/mysql.h 2006-05-25 11:56:42.000000000 +0300 +++ mysql-dfsg-5.0-5.0.24/include/mysql.h 2006-07-27 21:52:03.000000000 +0300 @@ -164,6 +164,7 @@ char *ssl_ca; /* PEM CA file */ char *ssl_capath; /* PEM directory of CA-s? */ char *ssl_cipher; /* cipher to use */ + my_bool ssl_verify_server_cert; /* if to verify server cert */ char *shared_memory_base_name; unsigned long max_allowed_packet; my_bool use_ssl; /* if to use SSL or not */

causes the size of st_mysql_options to grow. This also affects the MYSQL struct, since it contains st_mysql_options.

Now, libdbd-mysql-perl has this in dbdimp.h:

struct imp_dbh_st { dbih_dbc_t com; /* MUST be first element in structure */

MYSQL mysql; int has_transactions; /* boolean indicating support for * transactions, currently always * TRUE for MySQL and always FALSE * for mSQL. */ [...]

so the grown MYSQL struct overlaps with has_transactions.

This hits libdbd-mysql-perl 3.006-1, which is currently compiled against libmysqlclient15off-dev 5.0.22-x (with x depending on the architecture). When run with libmysqlclient15off 5.0.24-1, has_transactions gets reset to 0 and the result is 'Transactions not supported by database'. Recompiling libdbd-mysql-perl helps, as the API has not changed in an incompatible way.

In my understanding, the right fix is to bump the soname or to revert the struct st_mysql_options change.

Cheers,