set downloadMetadata.status to 404 on unfound downloads. fixes #1501

app/ui/download.js

@@ -85,9 +85,13 @@ module.exports = function(state, emit) {
   let content = '';
   if (!state.fileInfo) {
     state.fileInfo = createFileInfo(state);
-    if (!state.fileInfo.nonce) {
+    if (downloadMetadata.status === 404) {
       return notFound(state);
     }
+    if (!state.fileInfo.nonce) {
+      // coming from something like the browser back button
+      return location.reload();
+    }
   }
 
   if (state.fileInfo.dead) {

server/routes/pages.js

@@ -59,6 +59,15 @@ module.exports = {
 
   notfound: async function(req, res) {
     const appState = await state(req);
-    res.status(404).send(stripEvents(routes().toString('/404', appState)));
+    res
+      .status(404)
+      .send(
+        stripEvents(
+          routes().toString(
+            '/404',
+            Object.assign(appState, { downloadMetadata: { status: 404 } })
+          )
+        )
+      );
   }
 };