Media: Delete HEIC companion file when its attachment is deleted.

When the client-side media flow sideloads a HEIC original alongside a
JPEG derivative, the HEIC filename is stored in $metadata['original'].
wp_delete_attachment_files() only tracks 'original_image', so without
this hook the HEIC file would linger on disk after the attachment is
removed.

wp_delete_attachment_heic_companion_file() reads the meta key, guards
against non-string values (e.g. arrays written by other flows), and
deletes the file when present. Hooked into the delete_attachment
action via default-filters.php.

Backport of GB #76731, with the is_string() guard from GB #78128.

Author: adamsilverstein

src/wp-includes/default-filters.php

@@ -562,6 +562,7 @@
 add_action( 'transition_post_status', '_wp_customize_publish_changeset', 10, 3 );
 add_action( 'admin_enqueue_scripts', '_wp_customize_loader_settings' );
 add_action( 'delete_attachment', '_delete_attachment_theme_mod' );
+add_action( 'delete_attachment', 'wp_delete_attachment_heic_companion_file' );
 add_action( 'transition_post_status', '_wp_keep_alive_customize_changeset_dependent_auto_drafts', 20, 3 );
 
 // Block Theme Previews.

src/wp-includes/media.php

@@ -5760,6 +5760,45 @@ function wp_show_heic_upload_error( $plupload_settings ) {
 	return $plupload_settings;
 }
 
+/**
+ * Deletes the HEIC companion file when its attachment is deleted.
+ *
+ * When the client-side media flow sideloads a HEIC original alongside a
+ * JPEG derivative, the HEIC filename is recorded in $metadata['original'].
+ * WordPress only tracks 'original_image' in wp_delete_attachment_files(),
+ * so without this hook the HEIC file would linger on disk after the
+ * attachment is deleted.
+ *
+ * @since 7.1.0
+ *
+ * @param int $post_id Attachment ID being deleted.
+ */
+function wp_delete_attachment_heic_companion_file( $post_id ) {
+	$metadata = wp_get_attachment_metadata( $post_id, true );
+
+	if ( empty( $metadata['original'] ) || ! is_string( $metadata['original'] ) ) {
+		return;
+	}
+
+	$attached_file = get_attached_file( $post_id, true );
+
+	if ( ! $attached_file ) {
+		return;
+	}
+
+	$uploads = wp_get_upload_dir();
+
+	if ( empty( $uploads['basedir'] ) ) {
+		return;
+	}
+
+	$heic_path = path_join( dirname( $attached_file ), wp_basename( (string) $metadata['original'] ) );
+
+	if ( file_exists( $heic_path ) ) {
+		wp_delete_file_from_directory( $heic_path, $uploads['basedir'] );
+	}
+}
+
 /**
  * Allows PHP's getimagesize() to be debuggable when necessary.
  *