Fix uploaded files being previewed on wrong channels (#2860)

webapp/components/create_post.jsx

@@ -253,9 +253,11 @@ class CreatePost extends React.Component {
         draft.previews = draft.previews.concat(filenames);
         PostStore.storeDraft(channelId, draft);
 
-        this.setState({uploadsInProgress: draft.uploadsInProgress, previews: draft.previews});
+        if (channelId === this.state.channelId) {
+            this.setState({uploadsInProgress: draft.uploadsInProgress, previews: draft.previews});
+        }
     }
-    handleUploadError(err, clientId) {
+    handleUploadError(err, clientId, channelId) {
         let message = err;
         if (message && typeof message !== 'string') {
             // err is an AppError from the server
@@ -263,16 +265,18 @@ class CreatePost extends React.Component {
         }
 
         if (clientId !== -1) {
-            const draft = PostStore.getDraft(this.state.channelId);
+            const draft = PostStore.getDraft(channelId);
 
             const index = draft.uploadsInProgress.indexOf(clientId);
             if (index !== -1) {
                 draft.uploadsInProgress.splice(index, 1);
             }
 
-            PostStore.storeDraft(this.state.channelId, draft);
+            PostStore.storeDraft(channelId, draft);
 
-            this.setState({uploadsInProgress: draft.uploadsInProgress});
+            if (channelId === this.state.channelId) {
+                this.setState({uploadsInProgress: draft.uploadsInProgress});
+            }
         }
 
         this.setState({serverError: message});

webapp/components/file_upload.jsx

@@ -49,15 +49,15 @@ class FileUpload extends React.Component {
     fileUploadSuccess(channelId, data) {
         this.props.onFileUpload(data.filenames, data.client_ids, channelId);
 
-        const requests = JSON.parse(JSON.stringify(this.state.requests));
+        const requests = Object.assign({}, this.state.requests);
         for (var j = 0; j < data.client_ids.length; j++) {
             Reflect.deleteProperty(requests, data.client_ids[j]);
         }
         this.setState({requests});
     }
 
-    fileUploadFail(clientId, err) {
+    fileUploadFail(clientId, channelId, err) {
-        this.props.onUploadError(err, clientId);
+        this.props.onUploadError(err, clientId, channelId);
     }
 
     uploadFiles(files) {
@@ -86,7 +86,7 @@ class FileUpload extends React.Component {
                 channelId,
                 clientId,
                 this.fileUploadSuccess.bind(this, channelId),
-                this.fileUploadFail.bind(this, clientId)
+                this.fileUploadFail.bind(this, clientId, channelId)
             );
 
             const requests = this.state.requests;