[wp-trac] [WordPress Trac] #16617: Bulk activate plugins: add capabilities with WP_Roles::add_cap() fails, while procedural add_cap() does not

[WordPress Trac]

#16617: Bulk activate plugins: add capabilities with WP_Roles::add_cap() fails,
while procedural add_cap() does not
-----------------------------+------------------------------
 Reporter:  jrfoell          |       Owner:
     Type:  defect (bug)     |      Status:  new
 Priority:  normal           |   Milestone:  Awaiting Review
Component:  Role/Capability  |     Version:  3.0.5
 Severity:  normal           |  Resolution:
 Keywords:                   |
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Comment (by solarissmoke):

 Here's the problem:

 The function `get_role()` uses the global `$wp_roles`, which is
 instantiated the first time that `get_role()` is called. At instantiation,
 it loads the `wp_user_roles` option and stores it as `$wp_roles->roles`.

 Now, whenever you use $wp_roles::add_cap() (as the procedural plugin
 does), it simply adds the capability to `$wp_roles->roles`, and then does
 `update_option()` to store it in the database. If, in the mean time,
 something else has updated the `wp_user_roles` option independently (which
 is what the OO plugin does, with it's own instatiation of the WP_roles
 class), then $wp_roles has no knowledge of this and simply overwrites
 those changes. Hence the capability added by the OO plugin is overwritten.

 Basically, the current setup only works if you have *one* instantiation of
 the `WP_Roles` class. Things will break if plugin authors create their own
 - because the `wp_user_roles` option is loaded only once, at
 instantiation. Having two instances of the class making concurrent changes
 will always cause one set to be overwritten by the other.

 I'm no expert, but I can't see why you would want more than one instance
 of WP_Roles anyway?

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Ticket URL: <http://core.trac.wordpress.org/ticket/16617#comment:5>
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