WP_Query Category stuff blank page

[Ninos Ego]

hey there,
maybe I have found a bug. Sending following parameter to the WP Query (with my theme via ?s=test%cat=1234) you should get a blank page. At first I thought it was a bug of mine, but deleting following line in /wp-includes/query.php:1746 fixes the problem.

$q['category__in'][] = $cat;

So I think there's a bug in the query function...

Thanks,
Ninos

[alexvorn2]

so you want to say that there is a problem in filtering search results by category?
first of all why ?s=test%cat=1234 and not ?s=test&cat=1234

[markoheijnen]

Need more feedback. It sounds like you doing something wrong and without any details about errors there isn't something to say. Please test it out what is wrong with WP_DEBUG true.

[Ninos Ego]

Replying to alexvorn2:

first of all why ?s=test%cat=1234 and not ?s=test&cat=1234

sry typo :D

Replying to markoheijnen:

Need more feedback. It sounds like you doing something wrong and without any details about errors there isn't something to say. Please test it out what is wrong with WP_DEBUG true.

Debug was set to true, but there was no error. This bug is strange, I just get a blank page :/ In my theme I do not use the request "cat" anywhere, so I cannot understand, why this error happens.

My only clue is the line 1746 in the query.php...

[markoheijnen]

That is just random code. For what I can guess it seems a conflict with your theme or the plugins you are using.
I think your issue is better to be handled on ​http://wordpress.org/support/ and not here.

[SergeyBiryukov]

?s=test&cat=1234 throws two notices:

Notice: Trying to get property of non-object in wp-includes/general-template.php on line 1651
Notice: Trying to get property of non-object in wp-includes/general-template.php on line 1652

The code in question:
​http://core.trac.wordpress.org/browser/tags/3.5/wp-includes/general-template.php#L1648

Related: #18614, #21394

[markoheijnen]

Yeah confirmed that. Only happens when the category can't be found. looking to the code all calls to get_queried_object() are weird since there is no check at all.

That said that shouldn't cause a blank page.

[markoheijnen]

Added the patch for that fix to #21394.
Still more feedback of the user is needed on the reason why he gets a blank page. Do you get this where the cat is found or when it isn't found?

[Ninos Ego]

Think I have found the bug. Adding a non existing category id I get the descripted error.
On line /wp-includes/query.php:1745-1751 you should check the id:
just replace:

if ( $in ) {
	$q['category__in'][] = $cat;
	$q['category__in'] = array_merge( $q['category__in'], get_term_children($cat, 'category') );
} else {
	$q['category__not_in'][] = $cat;
	$q['category__not_in'] = array_merge( $q['category__not_in'], get_term_children($cat, 'category') );
}

with:

if( get_category($cat, false) ) {
	if ( $in ) {
		$q['category__in'][] = $cat;
		$q['category__in'] = array_merge( $q['category__in'], get_term_children($cat, 'category') );
	} else {
		$q['category__not_in'][] = $cat;
		$q['category__not_in'] = array_merge( $q['category__not_in'], get_term_children($cat, 'category') );
	}
}

Otherwise
$q['category__in'] or $q['category__not_in'] have got a wrong ID and send it in line /wp-includes/query.php:1761-1766

$tax_query[] = array(
	'taxonomy' => 'category',
	'terms' => $q['category__in'],
	'field' => 'term_id',
	'include_children' => false
);

and in line /wp-includes/query.php:1771-1776

$tax_query[] = array(
	'taxonomy' => 'category',
	'terms' => $q['category__not_in'],
	'operator' => 'NOT IN',
	'include_children' => false
);

to the tax query. Because of that I get a blank page.

[SergeyBiryukov]

Replying to Ninos Ego:

Otherwise $q['category__in'] or $q['category__not_in'] have got a wrong ID

That still shouldn't cause a blank page.

ticket:21394:21394.general-template.diff​ looks like the proper fix for the notice.

[markoheijnen]

Also that is not the problem. You should be able to send in non existing id's and that the query is going to listen to it.

And I agree with Sergey that it shouldn't cause a blank page. I think it's better you try to solve your problem through the forum and by that closing this ticket.

[Ninos Ego]

all my filters, plugins and action hooks are deactivated. I have deleted all query posts etc. but have not found the error in my theme. I think it's a wordpress bug, bacause my patch is working fine. But I will still search the bug in my theme, because other theme have not this problem...

[wonderboymusic]

#21394 has a patch in 3.7 that fixes a bunch of queried_object instances, let's focus the attention there