Ticket #56180: 56180.1.diff

src/wp-includes/theme.php

@@ -1179 +1179 @@
                 $url = get_random_header_image();
         }
 
+        /**
+         * Filters the header image URL.
+         *
+         * @since 6.1.0
+         *
+         * @param string $url Header image URL.
+         */
+        $url = apply_filters( 'header_image', $url );
+
+        if ( ! is_string( $url ) ) {
+                return false;
+        }
+
+        $url = trim( $url );
+
         return sanitize_url( set_url_scheme( $url ) );
 }
 

tests/phpunit/tests/theme/customHeader.php

@@ -119 +119 @@
                 $this->assertStringContainsString( sprintf( 'src="%s"', $custom ), $html );
         }
 
+        /**
+         * Tests the "header_image" filter.
+         *
+         * @ticket 56180
+         *
+         * @covers get_header_image
+         *
+         * @dataProvider data_filter_header_image
+         *
+         * @param mixed  $header_image The header image.
+         * @param string $expected     The expected return value from get_header_image().
+         */
+        public function test_filter_header_image( $header_image, $expected ) {
+                add_filter(
+                        'header_image',
+                        static function() use ( $header_image ) {
+                                return $header_image;
+                        }
+                );
+
+                $this->assertSame( $expected, get_header_image() );
+        }
+
+        /**
+         * Data provider.
+         *
+         * @return array
+         */
+        public function data_filter_header_image() {
+                return array(
+                        'an image url'         => array(
+                                'header_image' => 'http://example.org/image.png',
+                                'expected'     => 'http://example.org/image.png',
+                        ),
+                        'an empty string'      => array(
+                                'header_image' => '',
+                                'expected'     => '',
+                        ),
+                        'a string with spaces' => array(
+                                'header_image' => ' ',
+                                'expected'     => '',
+                        ),
+                        'null'                 => array(
+                                'header_image' => null,
+                                'expected'     => false,
+                        ),
+                        'false'                => array(
+                                'header_image' => false,
+                                'expected'     => false,
+                        ),
+                );
+        }
+
         public function test_get_custom_header_markup_without_registered_default_image() {
                 $this->add_theme_support();