Make WordPress Core

Opened 5 years ago

Last modified 4 months ago

#39678 new defect (bug)

get_term_by slug with "0" as value

Reported by: fausonealessio Owned by:
Milestone: Awaiting Review Priority: normal
Severity: normal Version: 4.7
Component: Taxonomy Keywords: has-patch has-unit-tests
Focuses: Cc:


Executing this code


my expectations were to obtain a taxonomy term, considering that one actually exists in my database, but instead the function returned false due to the PHP empty function returning true (see https://core.trac.wordpress.org/browser/tags/4.7/src/wp-includes/taxonomy.php#L844).
The empty function behaves according to documentation (http://php.net/manual/en/function.empty.php) but the string "0" should be accepted to be searched if it is possible to use it to create a taxonomy term.

Change History (2)

This ticket was mentioned in PR #1654 on WordPress/wordpress-develop by costdev.

5 months ago

  • Keywords has-patch has-unit-tests added

wp_insert_term() and wp_update_term() did not allow a term to be given a slug of (string) '0'.

This was due to:

  1. Sanitizing the provided value; this would turn (int) 0 into (string) '0'.
  2. Using empty() to check for an empty value; this returns true for (string) '0'.

This gave a false sense of security, as it correctly captured a disallowed value of (int) 0 and generated a slug from the term name. Unfortunately, this process also incorrectly prevented a value of (string) '0', which the docs suggest is an allowed value.

This patch:

  1. Stores whether or not the slug was (string) '0' prior to sanitization and adds this to an existing conditional (only in one case).
  2. Adds additional checks for '0' === $args['slug'], '0' !== $slug, etc. as needed.
  3. Adds unit tests for wp_insert_term() and wp_update_term().

Trac ticket: https://core.trac.wordpress.org/ticket/39678

This ticket was mentioned in Slack in #core by costdev. View the logs.

4 months ago

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