Media: Prevent PHP warnings in wp_get_missing_image_subsizes() when image dimensions are missing

src/wp-admin/includes/image.php

@@ -107,8 +107,9 @@ function wp_get_missing_image_subsizes( $attachment_id ) {
 		$full_width  = $imagesize[0];
 		$full_height = $imagesize[1];
 	} else {
-		$full_width  = (int) $image_meta['width'];
-		$full_height = (int) $image_meta['height'];
+		// Missing dimensions fall back to 0, so no sub-sizes are considered possible.
+		$full_width  = isset( $image_meta['width'] ) ? (int) $image_meta['width'] : 0;
+		$full_height = isset( $image_meta['height'] ) ? (int) $image_meta['height'] : 0;
 	}
 
 	$possible_sizes = array();

tests/phpunit/tests/media/wpGetMissingImageSubsizes.php

@@ -0,0 +1,149 @@
+<?php
+
+require_once ABSPATH . 'wp-admin/includes/image.php';
+
+/**
+ * Tests for the `wp_get_missing_image_subsizes()` function.
+ *
+ * @group media
+ * @covers ::wp_get_missing_image_subsizes
+ */
+class Tests_Media_wpGetMissingImageSubsizes extends WP_UnitTestCase {
+
+	/**
+	 * Creates an attachment with the given metadata, without uploading a real file.
+	 *
+	 * @param string $file      Attached file name.
+	 * @param string $mime_type Attachment mime type.
+	 * @param array  $meta      Attachment metadata.
+	 * @return int Attachment ID.
+	 */
+	private function create_attachment_with_meta( $file, $mime_type, $meta ) {
+		$attachment_id = self::factory()->attachment->create_object(
+			array(
+				'file'           => $file,
+				'post_mime_type' => $mime_type,
+			)
+		);
+
+		wp_update_attachment_metadata( $attachment_id, $meta );
+
+		return $attachment_id;
+	}
+
+	/**
+	 * Tests that missing width or height in the image meta does not trigger
+	 * an "Undefined array key" warning, and that no sub-sizes are reported
+	 * as missing when the full-size dimensions are unknown.
+	 *
+	 * @ticket 57813
+	 *
+	 * @dataProvider data_meta_without_dimensions
+	 *
+	 * @param string $file      Attached file name.
+	 * @param string $mime_type Attachment mime type.
+	 * @param array  $meta      Attachment metadata missing width and/or height.
+	 */
+	public function test_should_not_warn_when_dimensions_are_missing( $file, $mime_type, $meta ) {
+		$attachment_id = $this->create_attachment_with_meta( $file, $mime_type, $meta );
+
+		$this->assertSame( array(), wp_get_missing_image_subsizes( $attachment_id ) );
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array[]
+	 */
+	public function data_meta_without_dimensions() {
+		return array(
+			'svg with no dimensions'  => array(
+				'file'      => 'image.svg',
+				'mime_type' => 'image/svg+xml',
+				'meta'      => array(
+					'file'     => 'image.svg',
+					'filesize' => 1024,
+				),
+			),
+			'jpeg with no dimensions' => array(
+				'file'      => 'image.jpg',
+				'mime_type' => 'image/jpeg',
+				'meta'      => array(
+					'file'  => 'image.jpg',
+					'sizes' => array(),
+				),
+			),
+			'jpeg with no width'      => array(
+				'file'      => 'image.jpg',
+				'mime_type' => 'image/jpeg',
+				'meta'      => array(
+					'file'   => 'image.jpg',
+					'height' => 900,
+					'sizes'  => array(),
+				),
+			),
+			'jpeg with no height'     => array(
+				'file'      => 'image.jpg',
+				'mime_type' => 'image/jpeg',
+				'meta'      => array(
+					'file'  => 'image.jpg',
+					'width' => 1200,
+					'sizes' => array(),
+				),
+			),
+		);
+	}
+
+	/**
+	 * Tests that the `wp_get_missing_image_subsizes` filter still runs
+	 * when the image meta lacks width and height.
+	 *
+	 * @ticket 57813
+	 */
+	public function test_should_apply_filter_when_dimensions_are_missing() {
+		$attachment_id = $this->create_attachment_with_meta(
+			'image.jpg',
+			'image/jpeg',
+			array(
+				'file'  => 'image.jpg',
+				'sizes' => array(),
+			)
+		);
+
+		$filter = new MockAction();
+		add_filter( 'wp_get_missing_image_subsizes', array( $filter, 'filter' ), 10, 3 );
+
+		wp_get_missing_image_subsizes( $attachment_id );
+
+		$this->assertSame( 1, $filter->get_call_count(), 'The filter should be called once.' );
+
+		$args = $filter->get_args();
+		$this->assertSame( array(), $args[0][0], 'The filter should receive an empty array of missing sizes.' );
+		$this->assertSame( $attachment_id, $args[0][2], 'The filter should receive the attachment ID.' );
+	}
+
+	/**
+	 * Tests that sub-sizes are still reported as missing when the meta
+	 * has valid dimensions, so the guard for missing dimensions does not
+	 * short-circuit the normal path.
+	 *
+	 * @ticket 57813
+	 */
+	public function test_should_return_missing_sizes_when_dimensions_are_present() {
+		$attachment_id = $this->create_attachment_with_meta(
+			'image.jpg',
+			'image/jpeg',
+			array(
+				'file'   => 'image.jpg',
+				'width'  => 1200,
+				'height' => 900,
+				'sizes'  => array(),
+			)
+		);
+
+		$missing_sizes = wp_get_missing_image_subsizes( $attachment_id );
+
+		$this->assertNotEmpty( $missing_sizes, 'Sub-sizes should be reported as missing for an image with valid dimensions.' );
+		$this->assertArrayHasKey( 'thumbnail', $missing_sizes, 'The thumbnail size should be reported as missing.' );
+	}
+}