[web] Fix viewer close on deletion of last file (#5405)

server/compose.yaml

@@ -73,6 +73,8 @@ services:
 
 configs:
   credentials_yaml:
+    # You'll need to recreate the containers (docker compose down && docker
+    # compose up) when changing this inline config for the changes to apply.
     content: |
       db:
           host: postgres

web/packages/gallery/components/viewer/FileViewer.tsx

@@ -827,8 +827,10 @@ export const FileViewer: React.FC<FileViewerProps> = ({
     }, [handleClose, files]);
 
     useEffect(() => {
-        psRef.current?.refreshCurrentSlideFavoriteButtonIfNeeded();
-    }, [favoriteFileIDs, pendingFavoriteUpdates]);
+        if (open) {
+            psRef.current?.refreshCurrentSlideFavoriteButtonIfNeeded();
+        }
+    }, [favoriteFileIDs, pendingFavoriteUpdates, open]);
 
     useEffect(() => {
         if (open) {
@@ -840,7 +842,9 @@ export const FileViewer: React.FC<FileViewerProps> = ({
                 disableDownload,
                 haveUser,
                 delegate: delegateRef.current!,
-                onClose: handleClose,
+                onClose: () => {
+                    if (psRef.current) handleClose();
+                },
                 onAnnotate: handleAnnotate,
                 onViewInfo: handleViewInfo,
                 onDownload: handleDownloadBarAction,