STR:
  - Go to https://mozilla.github.io/pdf.js/web/viewer.html
  - Click on "Open File" and open a pdf

The `Download` button and the `Current view` one just disappear.
I can reproduce this bug with Firefox nightly, Chrome stable and Epiphany on debian.
break;
      }
    }
    if (params.has("pdfbug")) {
      AppOptions.set("pdfBug", true);
      AppOptions.set("fontExtraProperties", true);
      const enabled = params.get("pdfbug").split(",");
      waitOn.push(initPDFBug(enabled));
    }
    
    if (
      (typeof PDFJSDev === "undefined" ||
        PDFJSDev.test("!PRODUCTION || GENERIC")) &&
      params.has("locale")
    ) {
      AppOptions.set("locale", params.get("locale"));
    }
    if (waitOn.length === 0) {
      return;
    }
    try {
      await Promise.all(waitOn);
    } catch (reason) {
      console.error(`_parseHashParameters: "${reason.message}".`);
    }
  },
  /**
   * @private
   */
  async _initializeL10n() {