Taxonomy: Ensure term_exists respects $parent_term when $term is an integer.

This change updates `term_exists` by ensuring that any numeric value passed as the `$parent_term` argument is passed to the subsequent `get_terms` call when the `$term` argument is an integer.  This change includes unit tests to validate the fix.

Props spacedmonkey, lopo, lgadzhev, hugod, thehercules, nickbrazilian, audrasjb, vijendrajat, sachinrajcp123, bobbyleenoblestudios.
Fixes #55358.


git-svn-id: https://develop.svn.wordpress.org/trunk@60676 602fd350-edb4-49c9-b593-d223f7449a82

Author: dream-encode

src/wp-includes/taxonomy.php

@@ -1630,6 +1630,10 @@ function term_exists( $term, $taxonomy = '', $parent_term = null ) {
 	 */
 	$defaults = apply_filters( 'term_exists_default_query_args', $defaults, $term, $taxonomy, $parent_term );
 
+	if ( ! empty( $taxonomy ) && is_numeric( $parent_term ) ) {
+		$defaults['parent'] = (int) $parent_term;
+	}
+
 	if ( is_int( $term ) ) {
 		if ( 0 === $term ) {
 			return 0;
@@ -1642,10 +1646,6 @@ function term_exists( $term, $taxonomy = '', $parent_term = null ) {
 			return null;
 		}
 
-		if ( ! empty( $taxonomy ) && is_numeric( $parent_term ) ) {
-			$defaults['parent'] = (int) $parent_term;
-		}
-
 		$args  = wp_parse_args( array( 'slug' => sanitize_title( $term ) ), $defaults );
 		$terms = get_terms( $args );
 		if ( empty( $terms ) || is_wp_error( $terms ) ) {

tests/phpunit/tests/term/termExists.php

@@ -401,4 +401,153 @@ public function test_term_exists_unknown() {
 		$this->assertNull( term_exists( '' ) );
 		$this->assertNull( term_exists( null ) );
 	}
+
+	/**
+	 * @ticket 55358
+	 * @covers ::term_exists()
+	 */
+	public function test_term_exists_with_numeric_parent_term() {
+		register_taxonomy(
+			'foo',
+			'post',
+			array(
+				'hierarchical' => true,
+			)
+		);
+
+		$parent_term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'foo',
+			)
+		);
+
+		$child_term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'foo',
+				'parent'   => $parent_term,
+				'slug'     => 'child-term',
+			)
+		);
+
+		// Test with numeric parent_term as integer
+		$found = term_exists( 'child-term', 'foo', $parent_term );
+		$this->assertIsArray( $found );
+		$this->assertEquals( $child_term, $found['term_id'] );
+
+		// Test with numeric parent_term as string
+		$found = term_exists( 'child-term', 'foo', (string) $parent_term );
+		$this->assertIsArray( $found );
+		$this->assertEquals( $child_term, $found['term_id'] );
+
+		_unregister_taxonomy( 'foo' );
+	}
+
+	/**
+	 * @ticket 55358
+	 * @covers ::term_exists()
+	 */
+	public function test_term_exists_with_non_numeric_parent_term() {
+		register_taxonomy(
+			'foo',
+			'post',
+			array(
+				'hierarchical' => true,
+			)
+		);
+
+		$parent_term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'foo',
+			)
+		);
+
+		$child_term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'foo',
+				'parent'   => $parent_term,
+				'slug'     => 'child-term',
+			)
+		);
+
+		// Test with non-numeric parent_term (should not set parent filter)
+		$found = term_exists( 'child-term', 'foo', 'not-numeric' );
+		$this->assertIsArray( $found );
+		$this->assertEquals( $child_term, $found['term_id'] );
+
+		// Test with null parent_term (should not set parent filter)
+		$found = term_exists( 'child-term', 'foo', null );
+		$this->assertIsArray( $found );
+		$this->assertEquals( $child_term, $found['term_id'] );
+
+		_unregister_taxonomy( 'foo' );
+	}
+
+	/**
+	 * @ticket 55358
+	 * @covers ::term_exists()
+	 */
+	public function test_term_exists_with_empty_taxonomy_and_numeric_parent() {
+		register_taxonomy(
+			'foo',
+			'post',
+			array(
+				'hierarchical' => true,
+			)
+		);
+
+		$parent_term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'foo',
+			)
+		);
+
+		$child_term = self::factory()->term->create(
+			array(
+				'taxonomy' => 'foo',
+				'parent'   => $parent_term,
+				'slug'     => 'child-term',
+			)
+		);
+
+		// Test with empty taxonomy and numeric parent_term (should not set parent filter)
+		$found = term_exists( 'child-term', '', $parent_term );
+		$this->assertIsString( $found );
+		$this->assertEquals( $child_term, $found );
+
+		_unregister_taxonomy( 'foo' );
+	}
+
+	/**
+	 * @ticket 55358
+	 * @covers ::term_exists()
+	 */
+	public function test_term_exists_with_wordpress_categories() {
+		// Create a parent category
+		$parent_cat = self::factory()->term->create(
+			array(
+				'taxonomy' => 'category',
+				'name'     => 'Parent Category',
+				'slug'     => 'parent-category',
+			)
+		);
+
+		// Create a child category
+		$child_cat = self::factory()->term->create(
+			array(
+				'taxonomy' => 'category',
+				'name'     => 'Child Category',
+				'slug'     => 'child-category',
+				'parent'   => $parent_cat,
+			)
+		);
+
+		// Test finding child category with numeric parent
+		$found = term_exists( 'child-category', 'category', $parent_cat );
+		$this->assertIsArray( $found );
+		$this->assertEquals( $child_cat, $found['term_id'] );
+
+		// Test finding child category with wrong parent
+		$found = term_exists( 'child-category', 'category', 999 );
+		$this->assertNull( $found );
+	}
 }