Fix #5779 (Check database integrity is broken in 0.7 w/custom fields)

src/calibre/gui2/tag_view.py

@@ -609,7 +609,8 @@ class TagBrowserMixin(object): # {{{
         self.tags_view.saved_search_edit.connect(self.do_saved_search_edit)
         self.tags_view.tag_item_renamed.connect(self.do_tag_item_renamed)
         self.tags_view.search_item_renamed.connect(self.saved_search.clear_to_help)
-        self.edit_categories.clicked.connect(self.do_user_categories_edit)
+        self.edit_categories.clicked.connect(lambda x:
+                self.do_user_categories_edit())
 
     def do_user_categories_edit(self, on_category=None):
         d = TagCategories(self, self.library_view.model().db, on_category)

src/calibre/library/database2.py

@@ -1842,6 +1842,8 @@ books_series_link      feeds
             os.remove(self.dbpath)
             shutil.copyfile(dest, self.dbpath)
             self.connect()
+            self.field_metadata.remove_dynamic_categories()
+            self.field_metadata.remove_custom_fields()
             self.initialize_dynamic()
             self.refresh()
         if os.path.exists(dest):

src/calibre/library/field_metadata.py

@@ -379,6 +379,17 @@ class FieldMetadata(dict):
         self._add_search_terms_to_map(key, [key])
         self.custom_label_to_key_map[label] = key
 
+    def remove_custom_fields(self):
+        for key in self.get_custom_fields():
+            del self._tb_cats[key]
+
+    def remove_dynamic_categories(self):
+        for key in list(self._tb_cats.keys()):
+            val = self._tb_cats[key]
+            if val['is_category'] and val['kind'] in ('user', 'search'):
+                del self._tb_cats[key]
+
+
     def add_user_category(self, label, name):
         if label in self._tb_cats:
             raise ValueError('Duplicate user field [%s]'%(label))