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Date: Sat, 07 Jul 2012 08:20:38 -0700
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Subject: MYSQL_OPT_RECONNECT
From: rasmus@lerdorf.com (Rasmus Lerdorf)

I spent a bit of time looking at a mismatch between pdo_mysql and
MYSQL_OPT_RECONNECT. There is some rather odd code in
pdo_mysql/mysql_driver.c:

http://lxr.php.net/xref/PHP_5_4/ext/pdo_mysql/mysql_driver.c#640

There are two main problems here

1. This code is inside an if(driver_options) conditional so unless you
pass a driver option to the constructor this code doesn't get run. if it
wasn't for the second bug, we would have this odd side-effect behaviour
that setting any random option would also turn on automatic reconnects

2. The #ifdef MYSQL_OPT_RECONNECT doesn't work at all because MySQL
options are in an enum and thus obviously not available to the preprocessor.

So, because of these bugs when MySQL turned off auto-reconnects in 5.0.3
everyone has been running with them off despite pdo_mysql's intent to
turn them back on. Fixing these bugs now to make the code do what it was
intended to do would be a BC break. My suggestion is to just expose
MYSQL_OPT_RECONNECT as a normal user-settable option (which wouldn't be
available under mysqlnd) and leaving it off by default.

Looking through the bug db this was actually partially reported a while
ago in bug 58863. Johannes/Stas is exposing MYSQL_OPT_RECONNECT ok for
5.3/5.4? I suppose it is a grey area between a feature change and a bug
fix in this case.

-Rasmus