Media: Set HEIC upload support flag for canvas-based conversion

src/wp-includes/media.php

@@ -6603,6 +6603,14 @@ function wp_set_client_side_media_processing_flag(): void {
 
 	wp_add_inline_script( 'wp-block-editor', 'window.__clientSideMediaProcessing = true;', 'before' );
 
+	/*
+	 * Indicates that HEIC canvas-based upload support is available. Unlike the
+	 * full WebAssembly pipeline, this fallback does not require cross-origin
+	 * isolation, so browsers such as Safari can use createImageBitmap() to
+	 * decode HEIC images and convert them to JPEG before uploading.
+	 */
+	wp_add_inline_script( 'wp-block-editor', 'window.__heicUploadSupport = true;', 'before' );
+
 	$chromium_version = wp_get_chromium_major_version();
 
 	if ( null !== $chromium_version && $chromium_version >= 137 ) {

tests/phpunit/tests/media/wpSetClientSideMediaProcessingFlag.php

@@ -0,0 +1,123 @@
+<?php
+
+/**
+ * Tests for wp_set_client_side_media_processing_flag().
+ *
+ * @group media
+ * @covers ::wp_set_client_side_media_processing_flag
+ */
+class Tests_Media_wpSetClientSideMediaProcessingFlag extends WP_UnitTestCase {
+
+	/**
+	 * Original HTTP_USER_AGENT value.
+	 */
+	private ?string $original_user_agent;
+
+	/**
+	 * Original HTTP_HOST value.
+	 */
+	private ?string $original_http_host;
+
+	/**
+	 * Original HTTPS value.
+	 */
+	private ?string $original_https;
+
+	public function set_up() {
+		parent::set_up();
+		$this->original_user_agent = $_SERVER['HTTP_USER_AGENT'] ?? null;
+		$this->original_http_host  = $_SERVER['HTTP_HOST'] ?? null;
+		$this->original_https      = $_SERVER['HTTPS'] ?? null;
+
+		// Ensure client-side media processing is considered enabled.
+		$_SERVER['HTTP_HOST'] = 'localhost';
+
+		$GLOBALS['wp_scripts'] = new WP_Scripts();
+	}
+
+	public function tear_down() {
+		if ( null === $this->original_user_agent ) {
+			unset( $_SERVER['HTTP_USER_AGENT'] );
+		} else {
+			$_SERVER['HTTP_USER_AGENT'] = $this->original_user_agent;
+		}
+
+		if ( null === $this->original_http_host ) {
+			unset( $_SERVER['HTTP_HOST'] );
+		} else {
+			$_SERVER['HTTP_HOST'] = $this->original_http_host;
+		}
+
+		if ( null === $this->original_https ) {
+			unset( $_SERVER['HTTPS'] );
+		} else {
+			$_SERVER['HTTPS'] = $this->original_https;
+		}
+
+		unset( $GLOBALS['wp_scripts'] );
+
+		parent::tear_down();
+	}
+
+	/**
+	 * Returns the inline scripts added before the 'wp-block-editor' script.
+	 *
+	 * @return string Concatenated inline scripts, or an empty string if none.
+	 */
+	private function get_block_editor_before_scripts(): string {
+		$before = wp_scripts()->get_data( 'wp-block-editor', 'before' );
+
+		if ( ! is_array( $before ) ) {
+			return '';
+		}
+
+		return implode( "\n", array_filter( $before ) );
+	}
+
+	/**
+	 * @ticket 65648
+	 */
+	public function test_sets_heic_upload_support_flag_for_non_chromium_browsers() {
+		// Safari 26 on macOS.
+		$_SERVER['HTTP_USER_AGENT'] = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.0 Safari/605.1.15';
+
+		wp_set_client_side_media_processing_flag();
+
+		$before = $this->get_block_editor_before_scripts();
+
+		$this->assertStringContainsString( 'window.__clientSideMediaProcessing = true;', $before, 'The client-side media processing flag should be set.' );
+		$this->assertStringContainsString( 'window.__heicUploadSupport = true;', $before, 'The HEIC upload support flag should be set for non-Chromium browsers.' );
+		$this->assertStringNotContainsString( 'window.__documentIsolationPolicy', $before, 'The Document-Isolation-Policy flag should not be set for non-Chromium browsers.' );
+	}
+
+	/**
+	 * @ticket 65648
+	 */
+	public function test_sets_heic_upload_support_flag_for_chromium_browsers() {
+		$_SERVER['HTTP_USER_AGENT'] = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36';
+
+		wp_set_client_side_media_processing_flag();
+
+		$before = $this->get_block_editor_before_scripts();
+
+		$this->assertStringContainsString( 'window.__clientSideMediaProcessing = true;', $before, 'The client-side media processing flag should be set.' );
+		$this->assertStringContainsString( 'window.__heicUploadSupport = true;', $before, 'The HEIC upload support flag should be set for Chromium browsers.' );
+		$this->assertStringContainsString( 'window.__documentIsolationPolicy = true;', $before, 'The Document-Isolation-Policy flag should be set for Chromium 137+.' );
+	}
+
+	/**
+	 * @ticket 65648
+	 */
+	public function test_does_not_set_flags_when_client_side_media_processing_is_disabled() {
+		$_SERVER['HTTP_USER_AGENT'] = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.0 Safari/605.1.15';
+
+		add_filter( 'wp_client_side_media_processing_enabled', '__return_false' );
+
+		wp_set_client_side_media_processing_flag();
+
+		$before = $this->get_block_editor_before_scripts();
+
+		$this->assertStringNotContainsString( 'window.__clientSideMediaProcessing', $before, 'The client-side media processing flag should not be set when the feature is disabled.' );
+		$this->assertStringNotContainsString( 'window.__heicUploadSupport', $before, 'The HEIC upload support flag should not be set when the feature is disabled.' );
+	}
+}