Consider filtered URLs with arg in `wp_customize_url`

[xipasduarte]

The wp_customize_url function is setting the query string without proper handling of the URL that it receives from admin_url( 'customize.php' ). This leads to issues when the resulting URL contains a query string value. For example:

[...]/customize.php?my_custom_arg?theme=[theme_name]

When this happens it might generate a loop that results in the browser halting the page load with an error.

Adds theme arg using add_query_arg and takes care to remove any existing aruments with the same key.

Trac ticket: [](https://core.trac.wordpress.org/ticket/63632)

[westonruter]

@xipasduarte Thanks for reporting this. It makes sense to me. However, do you have an example where the URL has an initial query string? I know it. Would be introduced with filtering the admin URL, but is this an issue with any existing plugins or themes (or sites)?

[xipasduarte]

Thanks for the feedback @westonruter. I have an existing case in a plugin my company develops. It is meant as a translations plugin and we inject the param in the URL as a fallback mechanism for language detection. By doing this we broke the customizer link.

This is the plugin: ​https://github.com/26B/unbabble

It's not yet in the repository and we could kind of go around it and edit this link after, in another hook, but it made sense to me have this fixed in core, if any others need this. It seems to be what would be expected.

[westonruter]

@xipasduarte Thanks for the PR! I added a ​review. Feel free to skip also attaching a diff file to Trac. I personally almost always use GitHub branches when preparing commits for SVN, so keeping all your changes in the PR is just fine.

[xipasduarte]

@westonruter Thanks for the review. I believe I addressed everything and also added a few more tests. Take a look and let me know if we need to change anything else.

[westonruter]

In 60499:

Customize: Account for existing query params in the admin URL when wp_customize_url() adds the theme query param.

Query parameters may be inserted in the initial customize.php URL via the admin_url and site_url filters.

Props xipasduarte, westonruter.
Fixes #63632.

Trac ticket: https://core.trac.wordpress.org/ticket/63632

Follow-up to https://core.trac.wordpress.org/changeset/60499 commit.

[westonruter]

In 60500:

Customize: Use static closures in tests to reduce memory usage.

Follow-up to [60499].

Props mukesh27.
See #63632.

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 60500
GitHub commit: ​9672f54

This PR will be closed.