From dffc39cf0cb73aa1302f2e26a8551cdfe4da3595 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 9 Jan 2020 07:17:33 +0530
Subject: [PATCH] Viewer: Fix failure to open some books that contain
 unparseable URLs.  Fixes #1858836 [Viewer Crashes on "Invalid IPv6
 URL"](https://bugs.launchpad.net/calibre/+bug/1858836)

---
 src/calibre/srv/render_book.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/calibre/srv/render_book.py b/src/calibre/srv/render_book.py
index 4e0c5fb6bd..56b6802d88 100644
--- a/src/calibre/srv/render_book.py
+++ b/src/calibre/srv/render_book.py
@@ -106,7 +106,10 @@ def create_link_replacer(container, link_uid, changed):
                 return url
             changed.add(base)
             return resource_template.format(encode_url(base, frag))
-        purl = urlparse(url)
+        try:
+            purl = urlparse(url)
+        except Exception:
+            return url
         if purl.netloc or purl.query:
             return url
         if purl.scheme and purl.scheme != 'file':