From 02ff98d8dcf3223f27f39186b2ccc21b238bf478 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 1 Apr 2019 14:58:41 +0530
Subject: [PATCH] py3: Port DeVendor

---
 src/calibre/startup.py | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/src/calibre/startup.py b/src/calibre/startup.py
index a6911b9f29..02ef35deee 100644
--- a/src/calibre/startup.py
+++ b/src/calibre/startup.py
@@ -17,15 +17,16 @@ builtins.__dict__['_'] = lambda s: s
 # immediately translated to the environment language
 builtins.__dict__['__'] = lambda s: s
 
-from calibre.constants import iswindows, preferred_encoding, plugins, isosx, islinux, isfrozen, DEBUG, isfreebsd
+from calibre.constants import iswindows, preferred_encoding, plugins, isosx, islinux, isfrozen, DEBUG, isfreebsd, ispy3
 
 _run_once = False
 winutil = winutilerror = None
 
 if not _run_once:
     _run_once = True
+    from importlib import import_module
 
-    if not isfrozen:
+    if not isfrozen and not ispy3:
         # Prevent PyQt4 from being loaded
         class PyQt4Ban(object):
 
@@ -40,15 +41,28 @@ if not _run_once:
 
     class DeVendor(object):
 
-        def find_module(self, fullname, path=None):
-            if fullname == 'calibre.web.feeds.feedparser' or fullname.startswith('calibre.ebooks.markdown'):
-                return self
+        if ispy3:
 
-        def load_module(self, fullname):
-            from importlib import import_module
-            if fullname == 'calibre.web.feeds.feedparser':
-                return import_module('feedparser')
-            return import_module(fullname[len('calibre.ebooks.'):])
+            def find_spec(self, fullname, path, target=None):
+                spec = None
+                if fullname == 'calibre.web.feeds.feedparser':
+                    m = import_module('feedparser')
+                    spec = m.__spec__
+                elif fullname.startswith('calibre.ebooks.markdown'):
+                    m = import_module(fullname[len('calibre.ebooks.'):])
+                    spec = m.__spec__
+                return spec
+
+        else:
+
+            def find_module(self, fullname, path=None):
+                if fullname == 'calibre.web.feeds.feedparser' or fullname.startswith('calibre.ebooks.markdown'):
+                    return self
+
+            def load_module(self, fullname):
+                if fullname == 'calibre.web.feeds.feedparser':
+                    return import_module('feedparser')
+                return import_module(fullname[len('calibre.ebooks.'):])
 
     sys.meta_path.insert(0, DeVendor())