fixed video thumbnail generation to have a lock that prevents multiple attempts to create the thumbnails at the same time. fixed ImageUpload to catch resize errors and not crash the server.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/client/views/collections/CollectionStackedTimeline.tsx b/src/client/views/collections/CollectionStackedTimeline.tsx
index 714d8421a..52126884a 100644
--- a/src/client/views/collections/CollectionStackedTimeline.tsx
+++ b/src/client/views/collections/CollectionStackedTimeline.tsx
@@ -2,7 +2,7 @@ import React = require('react');
 import { action, computed, IReactionDisposer, observable, reaction } from 'mobx';
 import { observer } from 'mobx-react';
 import { computedFn } from 'mobx-utils';
-import { Doc, DocListCast } from '../../../fields/Doc';
+import { Doc, DocListCast, StrListCast } from '../../../fields/Doc';
 import { Id } from '../../../fields/FieldSymbols';
 import { List } from '../../../fields/List';
 import { listSpec } from '../../../fields/Schema';
@@ -289,10 +289,9 @@ export class CollectionStackedTimeline extends CollectionSubView<CollectionStack
             this._hoverTime = this.toTimeline(clientX - rect.x, rect.width);
             if (this.dataDoc.thumbnails) {
                 const nearest = Math.floor((this._hoverTime / this.props.rawDuration) * VideoBox.numThumbnails);
-                const thumbnails = Cast(this.dataDoc.thumbnails, listSpec('string'), []);
-                const imgField = thumbnails && thumbnails.length > 0 ? new ImageField(thumbnails[nearest]) : new ImageField('');
-                const src = imgField && imgField.url.href ? imgField.url.href.replace('.png', '_s.png') : '';
-                this._thumbnail = src ? src : undefined;
+                const thumbnails = StrListCast(this.dataDoc.thumbnails);
+                const imgField = thumbnails?.length > 0 ? new ImageField(thumbnails[nearest]) : undefined;
+                this._thumbnail = imgField?.url?.href ? imgField.url.href.replace('.png', '_s.png') : undefined;
             }
         }
     };