Media: add x-wav mime type for wav files in Firefox (WordPress#66850)

Adding x-wav support because Firefox uses that identifier
Check if wav does not exist in case some plugins or themes have already filtered it out.

Co-authored-by: ramonjd <[email protected]>
Co-authored-by: Imran92 <[email protected]>

backport-changelog/6.8/7265.md

@@ -0,0 +1,3 @@
+https://github.com/WordPress/wordpress-develop/pull/7265
+
+* https://github.com/WordPress/gutenberg/pull/66850

lib/compat/wordpress-6.8/functions.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * Adds the x-wav mime type to the list of mime types.
+ * This is necessary for Firefox as it uses the identifier for uploaded .wav files.
+ * Core backport should add the following to the default mime_types filters in
+ * `wp_get_mime_types()` in wp-includes/functions.php:
+ *
+ * `'wav|x-wav' => 'audio/wav'`
+ *
+ * @since 6.8.0
+ *
+ * @param string[] $mime_types Mime types.
+ * @return string[] Mime types keyed by the file extension regex corresponding to those types.
+*/
+function gutenberg_get_mime_types_6_8( $mime_types ) {
+	/*
+	 * Only add support if there is existing support for 'wav'.
+	 * Some plugins may have deliberately disabled it.
+	*/
+	if ( ! $mime_types['wav'] && ! isset( $mime_types['wav|x-wav'] ) ) {
+		return $mime_types;
+	}
+	/*
+	 * Also, given that other themes or plugins may have already
+	 * tried to add x-wav type support, only
+	 * add the mime type if it doesn't already exist
+	 * to avoid overriding any customizations.
+	 */
+	if ( ! isset( $mime_types['x-wav'] ) && ! isset( $mime_types['wav|x-wav'] ) ) {
+		$mime_types['x-wav'] = 'audio/wav';
+	}
+	return $mime_types;
+}
+add_filter( 'mime_types', 'gutenberg_get_mime_types_6_8', 99 );

lib/load.php

@@ -119,6 +119,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 // WordPress 6.8 compat.
 require __DIR__ . '/compat/wordpress-6.8/preload.php';
 require __DIR__ . '/compat/wordpress-6.8/blocks.php';
+require __DIR__ . '/compat/wordpress-6.8/functions.php';
 
 // Experimental features.
 require __DIR__ . '/experimental/block-editor-settings-mobile.php';