User destination fails -- tries to insert '' into users.uid

I wasn't able to track down the cause of the problem today, but I'll investigate more tomorrow. Any ideas?

The WineUser migration gives the same error, with each item failing. I'm on dbtng-6.x-1.0-alpha7. I tried alpha6 (no go, it crashes), checking out DRUPAL-6--1 dbtng, same result. I'll assume for now dbtng isn't the problem and I'll step through the migration code.

Seems to be because of what might be considered a bug in user_save(): if isset($array['uid']), then core will add uid to the query as a string (thus '%s' with NULL becomes ''). Ugh. I don't see an issue filed in core for this, though. It's bitten me before, actually, and I thought of it as simply a quirk.

Here's a patch for migrate that mitigates the problem.

My patch is fine (it is as intended; I've used it with drush make already) -- check out the logic in Drupal 6's user_save() to see why $account['uid'] being set (even set to NULL) causes user_save() to generate a broken query....

OK. I just tried mysql> INSERT INTO users (uid, name, mail) VALUES ('', 'foo', 'bar'); in three different environments.

Apparently, inserting '' for uid works only in some MySQL versions. I'm using MariaDB on my development machine, but I'm not sure if the problem is Maria, or if it's the version of MySQL this Maria is based on. Perhaps a configuration setting that makes warning 1366 an error.

My development machine:

• Ubuntu 9.10 i686, PHP 5.2.10-2ubuntu6.5 with Suhosin-Patch 0.9.7
• mysql Ver 14.16 Distrib 5.1.49-MariaDB, for debian-linux-gnu (i486) using readline 5.1

MariaDB [sandbox_ni]> INSERT INTO users (uid, name, mail) VALUES ('', 'foo', 'bar');
ERROR 1366 (HY000): Incorrect integer value: '' for column 'uid' at row 1

Two other environments both succeed with a warning:

• Ubuntu 8.04 x86_64, mysql Ver 14.12 Distrib 5.0.51a, for debian-linux-gnu (x86_64) using readline 5.2
• Ubuntu 10.04.1 LTS i686, mysql Ver 14.14 Distrib 5.1.41, for debian-linux-gnu (i486) using readline 6.1

mysql> \W
Show warnings enabled.
mysql> INSERT INTO users (uid, name, mail) VALUES ('', 'foo', 'bar');
Query OK, 1 row affected, 1 warning (0.05 sec)

Warning (Code 1366): Incorrect integer value: '' for column 'uid' at row 1

So I think the question is: Should trying to insert '' for uid be considered a bug in migrate?

The problem is back in 6.x-2.0-rc2 due to this new code:

    // Avoid a notice
    if (!isset($account->uid)) {
      $account->uid = NULL;
    }

I think that D6's user_save() isn't going to let that notice be avoided *and* generate the proper query. (Maybe there is a way, I don't know, but for now I have to patch migrate.)

I've rerolled and attached a new patch.

Whoops -- I guess hitting "Preview" when attaching a file was a bad idea. Here's the patch.