From 7f308db1d288f21dc16f6af9721e518a77653a96 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 16 Jul 2009 14:49:36 -0600
Subject: [PATCH] Fix subtle bug that would cause problems when using multiple
 plumbers in the same process, as happens when importing HTML files in the GUI

---
 src/calibre/ebooks/conversion/plumber.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/calibre/ebooks/conversion/plumber.py b/src/calibre/ebooks/conversion/plumber.py
index 39170c69b5..3c49cc9423 100644
--- a/src/calibre/ebooks/conversion/plumber.py
+++ b/src/calibre/ebooks/conversion/plumber.py
@@ -465,6 +465,12 @@ OptionRecommendation(name='list_recipes',
 
         # Remove the options that have been disabled by recommendations from the
         # plugins.
+        for w in ('input_options', 'output_options',
+                'all_format_options'):
+            temp = set([])
+            for x in getattr(self, w):
+                temp.add(x.clone())
+            setattr(self, w, temp)
         self.merge_plugin_recommendations()
 
     @classmethod