From c6509de909d15a0535d395bacef5bc5a50505ddb Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 24 Jan 2013 19:34:47 +0530
Subject: [PATCH] ...

---
 src/calibre/db/categories.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/calibre/db/categories.py b/src/calibre/db/categories.py
index 092b6da877..ec4725ff9f 100644
--- a/src/calibre/db/categories.py
+++ b/src/calibre/db/categories.py
@@ -113,6 +113,16 @@ def get_categories(dbcache, sort='name', book_ids=None, icon_map=None):
         cats.sort(key=key)
         categories[category] = cats
 
+    # Needed for legacy databases that have multiple ratings that
+    # map to n stars
+    for r in categories['rating']:
+        for x in tuple(categories['rating']):
+            if r.name == x.name and r.id != x.id:
+                r.id_set |= x.id_set
+                r.count = r.count + x.count
+                categories['rating'].remove(x)
+                break
+
     return categories