From 1030fb4bfa5cfa3f0f00ae11ec8c981d91a4b41d Mon Sep 17 00:00:00 2001
From: Charles Haley <>
Date: Sun, 13 Jun 2010 05:44:53 +0100
Subject: [PATCH] Fix for bug #5809

---
 src/calibre/gui2/dialogs/metadata_single.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/calibre/gui2/dialogs/metadata_single.py b/src/calibre/gui2/dialogs/metadata_single.py
index 0241e1b542..0e35f938dd 100644
--- a/src/calibre/gui2/dialogs/metadata_single.py
+++ b/src/calibre/gui2/dialogs/metadata_single.py
@@ -357,7 +357,8 @@ class MetadataSingleDialog(ResizableDialog, Ui_MetadataSingleDialog):
         aus = self.db.author_sort(row)
         self.author_sort.setText(aus if aus else '')
         tags = self.db.tags(row)
-        self.tags.setText(', '.join(tags.split(',')) if tags else '')
+        self.original_tags = ', '.join(tags.split(',')) if tags else ''
+        self.tags.setText(self.original_tags)
         self.tags.update_tags_cache(self.db.all_tags())
         rating = self.db.rating(row)
         if rating > 0:
@@ -527,6 +528,10 @@ class MetadataSingleDialog(ResizableDialog, Ui_MetadataSingleDialog):
             self.publisher.setCurrentIndex(idx)
 
     def edit_tags(self):
+        if self.tags.text() != self.original_tags:
+            error_dialog(self, _('Cannot use tag editor'),
+                _('The tags editor cannot be used if you have modified the tags')).exec_()
+            return
         d = TagEditor(self, self.db, self.row)
         d.exec_()
         if d.result() == QDialog.Accepted: