From 31e2bc3818b888503b14c025230c7468e3dcad78 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 11 May 2011 09:53:28 -0600
Subject: [PATCH] Fix #781135 (ParseException when pressing "Next" or
 "Previous" in plugin search)

---
 src/calibre/gui2/preferences/plugins.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/calibre/gui2/preferences/plugins.py b/src/calibre/gui2/preferences/plugins.py
index 8888a64e84..4f88e5aa1d 100644
--- a/src/calibre/gui2/preferences/plugins.py
+++ b/src/calibre/gui2/preferences/plugins.py
@@ -75,6 +75,8 @@ class PluginModel(QAbstractItemModel, SearchQueryParser): # {{{
 
     def find(self, query):
         query = query.strip()
+        if not query:
+            return QModelIndex()
         matches = self.parse(query)
         if not matches:
             return QModelIndex()
@@ -87,6 +89,8 @@ class PluginModel(QAbstractItemModel, SearchQueryParser): # {{{
 
     def find_next(self, idx, query, backwards=False):
         query = query.strip()
+        if not query:
+            return idx
         matches = self.parse(query)
         if not matches:
             return idx