extend_dict hooks cannot be overriden by subclasses

[Salvatore Orlando]

The extend_dict hooks are registered as unbound methods which means that any subclass of a mixin will cause an unintended registration of the parent class hooks - calling the extend_xxx_dict method to be invoked even if the actual plugin class does not define one.

This is pretty much the same thing as bug 1210387 - applies to extend_dict functions rather than model hooks.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44778

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44778
Committed: http://github.com/openstack/neutron/commit/a07bbac1c40dd4f748fe9a40f8adb3654b3ed8e3
Submitter: Jenkins
Branch: master

commit a07bbac1c40dd4f748fe9a40f8adb3654b3ed8e3
Author: Salvatore Orlando <email address hidden>
Date: Mon Sep 2 17:37:22 2013 -0700

    Allow subclasses to modify dict_extend hooks

    Partial-Bug 1219991

    This change modifies the hook processing for dict_extend routines
    to call the method on the instance if a hook is registered as a string.
    Otherwise, the callable hook is directly invoked as an unbound method.

    This patch fixes hook registration for all extensions except port_binding.
    This is because some plugins are currently working around this limitation
    by invoking both the global hook and another dict_extend function,
    which might either be registered as another hook, or invoked explicitly
    before returning the response.
    Fixing this would go beyong the scope of this patch.

    Change-Id: Ibe78433e6554aa7fdf5156fc75b8339254876e78

[Salvatore Orlando (salvatore-orlando)]

put partial-bug by mistake in commit msg.