Files not persisting in uploader if form has errors

So I'm using Pluploader in a custom Form. I've noticed that when files are attached and then the form is submitted (with form errors), when it refreshes the page, the files are no longer there.

To fix this, I added some custom code that fetched the form_state values, passed them to a custom js file via Drupal.settings js, and then added them as already-completed to the pluploader object. Here is the code I used (you'll have to use your own form ids and whatnot, of course):

In the drupal form creation function:

	// If there were any previously-uploaded files, re-attach them via js here.
	$count = 0;
	$files = array();

	while( isset($form_state['input']['edit-step4-data_'.$count.'_tmpname']) ) {
		$id = explode('.', $form_state['input']['edit-step4-data_'.$count.'_tmpname']);

		// Get the file size.
		$size = filesize( drupal_realpath('temporary://'.$id[0].'.tmp') );

		$files[] = array(
			'id' => $id[0],
			'name' => $form_state['input']['edit-step4-data_'.$count.'_name'],
			'size' => $size,
		);

		$count++;
	}

	if ( !isset($form['#attached']) ) { $form['#attached'] = array(); }
	if ( !isset($form['#attached']['js']) ) { $form['#attached']['js'] = array(); }

	$form['#attached']['js'][] = array(
		'data' => array(
			'bcrsp_cmp_files' => $files,
		),
		'type' => 'setting',
	);

	$form['#attached']['js'][] = drupal_get_path('module', 'bcrsp_cmp') . '/js/bcrsp_cmp_new_activity_page.js';

and the javascript file:

(function ($) {
	Drupal.behaviors.bcrsp_cmp_new_activity_page = {
		attach: function (context, settings) {
			// Get the Plupload object.
			var uploader = jQuery(".plupload-element", context).pluploadQueue();

			// Add previous files to uploader (flag as uploaded, as they already were).
			for ( var i = 0; i < Drupal.settings.bcrsp_cmp_files.length; i++ ) {
				var file = Drupal.settings.bcrsp_cmp_files[i];
				var new_file = new plupload.File (file.id, file.name, file.size);
			
				// Add extra data to the file to say it's already uploaded (which it is, since it was passed in from form_state).
				new_file.status = plupload.DONE;
				new_file.loaded = new_file.size;
				new_file.percent = 100;

				// Push the file into the uploader's file list.
				uploader.files.push( new_file );

				// Trigger that an upload happened so that form_state gets properly filled.
				uploader.trigger("UploadFile", new_file );
			}

			// Update the uploader to reflect the new files.
			if ( uploader.files.length > 0 ) {
				var files_loaded = 0;

				// Add up the total bytes that were uploaded.
				for( var i = 0; i < uploader.files.length; i++) {
					files_loaded += uploader.files[i].loaded;
				}

				// Update the queue progress to reflect the files that are updated.
				var queueprogress = uploader.total;
				queueprogress.size = files_loaded;
				queueprogress.loaded = files_loaded;
				queueprogress.uploaded = uploader.files.length;
				queueprogress.percent = 100;

				// Refresh the uploader so it shows the new files and percentages.
				uploader.trigger("QueueChanged");
				uploader.refresh();
			}
		}
	};
})(jQuery);

If I just missed something in my setup to make this work out-of-the-box, let me know. Otherwise, I'll add it to the plupload project and put up the patch here.