From ee5d98d5d00495d36099227266af50332da76cd7 Mon Sep 17 00:00:00 2001
From: Florian Bruhin <me@the-compiler.org>
Date: Sat, 22 Sep 2018 20:10:57 +0200
Subject: [PATCH] Make sure PDF.js doesn't try to use the Fetch API

Closes #4235
---
 qutebrowser/browser/pdfjs.py | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/qutebrowser/browser/pdfjs.py b/qutebrowser/browser/pdfjs.py
index ee291d4eb..cfc15a35b 100644
--- a/qutebrowser/browser/pdfjs.py
+++ b/qutebrowser/browser/pdfjs.py
@@ -56,11 +56,18 @@ def generate_pdfjs_page(filename, url):
         return jinja.render('no_pdfjs.html',
                             url=url.toDisplayString(),
                             title="PDF.js not found")
-    viewer = get_pdfjs_res('web/viewer.html').decode('utf-8')
+    html = get_pdfjs_res('web/viewer.html').decode('utf-8')
+
     script = _generate_pdfjs_script(filename)
-    html_page = viewer.replace('</body>',
-                               '</body><script>{}</script>'.format(script))
-    return html_page
+    html = html.replace('</body>',
+                        '</body><script>{}</script>'.format(script))
+    # WORKAROUND for the fact that PDF.js tries to use the Fetch API even with
+    # qute:// URLs.
+    pdfjs_script = '<script src="../build/pdf.js"></script>'
+    html = html.replace(pdfjs_script,
+                        '<script>window.Response = undefined;</script>\n' +
+                        pdfjs_script)
+    return html
 
 
 def _generate_pdfjs_script(filename):