id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
12492	Improper use of a variable variable ($$) in remove_all_filters()	chrisbliss18	westi	"In wp-includes/plugin.php's remove_all_filters function are the following lines of code:

{{{
if( false !== $priority && isset($$wp_filter[$tag][$priority]) )
    unset($wp_filter[$tag][$priority]);
}}}

The $$ is a [http://www.php.net/manual/en/language.variables.variable.php variable variable], which is clearly a typo in this case given the next line. I first found this when the following warning was generated by trying to make use of the priority option of remove_all_actions:

  Notice: Array to string conversion in /opt/lampp/htdocs/trunk/wp-includes/plugin.php  on line 225

Since this amounts to checking for variables of type $false, $10, or any other given argument, which won't exist, the second argument is currently useless. Thus, until the supplied patch is implemented, it won't be possible to use remove_all_filters or remove_all_actions to remove all hooks of a specific priority.

A sample plugin showing this bug is attached. The sample plugin hooks the same function to the template_redirect action three times with priorities of default, 20, and 30. It then uses the remove_all_actions function (which simply calls remove_all_filters) to remove all template_redirect hooks for priority 10. This should result in the hooked function being called twice, but produces nothing as all the hooks are cleared.

With my supplied patch applied, the hooked function is called twice, echoing ""This should render twice."" each time. Thus, the expected result is achieved with this patch."	defect (bug)	closed	normal	3.0	Plugins	3.0	normal	fixed	has-patch tested commit	gaarai@…