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Opened 5 years ago

Closed 5 years ago

#15774 closed defect (bug) (fixed)

Don't Double URL Query Args in Canonical Redirect

Reported by: filosofo Owned by: MarkJaquith
Milestone: 3.1 Priority: normal
Severity: normal Version: 3.1
Component: Canonical Keywords: has-patch
Focuses: Cc:


Currently, when using "default" permalinks and requesting something that triggers canonical redirect, the query portion of the request URL can double up the same request arguments, which leads to redirect_canonical()'s returning falsely different URLs.

In other words, suppose you have a custom post type of custom_post_thing with an object that has a slug a-custom-post-thingy-title and an ID of 123.

If you request /?p=123 redirect_canonical() figures out that its correct, canonical URL is actually


However, when redirect_canonical() is called again at line 362, it appends the same query value to the fetched URL, like so:


The result is that




differ as strings even though they're the same in actual meaning, and the redirect fails and a 404 results.

(I have seen this happen in other redirect situations--it's not limited to custom post types.)

The patch parses the redirect URL's query value and uses add_query_arg() to add it, rather than the current naive string concatenation. The result is that arguments do not get doubled, and the redirect succeeds.

Attachments (1)

do-not-double-redirect-query.15774.diff (679 bytes) - added by filosofo 5 years ago.

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Change History (5)

comment:1 @filosofo5 years ago

It's also worth pointing out that the current behavior results in differing behavior between default permalinks and pretty permalinks. With pretty permalinks canonical will correctly redirect a request like /?p=123 above; with the default ones, it fails to redirect and produces a 404.

comment:2 @filosofo5 years ago

Note: #15775 uses the patch here. Committing #15775 will fix this ticket as well.

comment:3 @nacin5 years ago

  • Owner set to MarkJaquith
  • Status changed from new to assigned

comment:4 @markjaquith5 years ago

  • Resolution set to fixed
  • Status changed from assigned to closed

(In [17030]) Do not add URL query args twice in certain Canonical Redirect situations. Use add_query_arg(). props filosofo. fixes #15774

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