INSTANCE OF now behaves correctly by including all possible child classes in IN() filtering conditions

[taueres]

There was a bug in the "INSTANCE OF" operator as described in
https://groups.google.com/forum/#!topic/doctrine-user/B8raq8CNMgg

"INSTANCE OF" was not taking into account subclasses.
It was merely translating the class to its discriminator.
This is not correct since the class can have subtypes and those
are, indeed, still instance of the superclass.
Also, classes may not have a discriminator (e.g. abstract classes).

This commit also provides useful tests to avoid regression.

[doctrinebot]

Hello,

thank you for creating this pull request. I have automatically opened an issue
on our Jira Bug Tracker for you. See the issue link:

http://www.doctrine-project.org/jira/browse/DDC-3800

We use Jira to track the state of pull requests and the versions they got
included in.

[stof]

IIRC, the doc mentions that inheritance is not taken into account for this operator.
This change is technically a BC break for anyone relying on the current behavior.

[taueres]

There's also an additional problem. If classes are parametrized they won't be converted to slugs since they are passed directly to connection level statement.

[taueres]

@stof Docs do not say much about "instance of" operator. I found only this reference: http://doctrine-orm.readthedocs.org/en/latest/reference/dql-doctrine-query-language.html

[peelandsee]

quoting @Ocramius in https://groups.google.com/d/msg/doctrine-user/B8raq8CNMgg/kYeSR7gC1Y4J
i think the same: it's a bug!

this fix could simplify a lot of existing code,
where you have to manually build an external hierarchical discrimination map from entity classes,
to prepare your DQL..

if current behavior it's not mentioned in the docs (so the bug was also undocumented),
IMHO this should not be considered a BC..

[Jean85]

It shouldn't also be considered a BC because if you try to do an INSTANCEOF now on (for example) an abstract class, it does not provide a "current behavior"; it simply throws an exception, because it can't find any discriminator associated to the abstract class itself.

[peelandsee]

any chance to merge this?

PR was motivated by https://groups.google.com/d/msg/doctrine-user/B8raq8CNMgg/kYeSR7gC1Y4J

thanks!

[Jean85]

Hi there... no news here?
In the meantime, DoctrineBot migrated the issue into #4646

[taueres]

I'm closing this PR in favor of the newer #6392

[Ocramius]

Handled in #6392