Fix crash if a notification contains an unprocessed media attachment (#16573)

* Refactor AttachmentList

* Do not crash if a notification contains an unprocessed media attachment

Fixes #16530

* Fix spacing in compact form

app/javascript/mastodon/components/attachment_list.js

@@ -2,6 +2,8 @@ import React from 'react';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import PropTypes from 'prop-types';
 import ImmutablePureComponent from 'react-immutable-pure-component';
+import { FormattedMessage } from 'react-intl';
+import classNames from 'classnames';
 import Icon from 'mastodon/components/icon';
 
 const filename = url => url.split('/').pop().split('#')[0].split('?')[0];
@@ -16,29 +18,13 @@ export default class AttachmentList extends ImmutablePureComponent {
   render () {
     const { media, compact } = this.props;
 
-    if (compact) {
     return (
-        <div className='attachment-list compact'>
-          <ul className='attachment-list__list'>
-            {media.map(attachment => {
-              const displayUrl = attachment.get('remote_url') || attachment.get('url');
-
-              return (
-                <li key={attachment.get('id')}>
-                  <a href={displayUrl} target='_blank' rel='noopener noreferrer'><Icon id='link' /> {filename(displayUrl)}</a>
-                </li>
-              );
-            })}
-          </ul>
-        </div>
-      );
-    }
-
-    return (
-      <div className='attachment-list'>
+      <div className={classNames('attachment-list', { compact })}>
+        {!compact && (
           <div className='attachment-list__icon'>
             <Icon id='link' />
           </div>
+        )}
 
         <ul className='attachment-list__list'>
           {media.map(attachment => {
@@ -46,7 +32,11 @@ export default class AttachmentList extends ImmutablePureComponent {
 
             return (
               <li key={attachment.get('id')}>
-                <a href={displayUrl} target='_blank' rel='noopener noreferrer'>{filename(displayUrl)}</a>
+                <a href={displayUrl} target='_blank' rel='noopener noreferrer'>
+                  {compact && <Icon id='link' />}
+                  {compact && ' ' }
+                  {displayUrl ? filename(displayUrl) : <FormattedMessage id='attachments_list.unprocessed' defaultMessage='(unprocessed)' />}
+                </a>
               </li>
             );
           })}