Enhancement: arbitrary searches as search restrictions

Bug fix: invalid search restrictions no longer break the tag browser

src/calibre/gui2/search_box.py

@@ -443,6 +443,7 @@ class SavedSearchBoxMixin(object): # {{{
         # rebuild the restrictions combobox using current saved searches
         self.search_restriction.clear()
         self.search_restriction.addItem('')
+        self.search_restriction.addItem(_('*Current search'))
         if recount:
             self.tags_view.recount()
         for s in p:

src/calibre/gui2/search_restriction_mixin.py

@@ -29,13 +29,32 @@ class SearchRestrictionMixin(object):
             self.search_restriction.setCurrentIndex(r)
             self.apply_search_restriction(r)
 
-    def apply_search_restriction(self, i):
-        r = unicode(self.search_restriction.currentText())
-        if r is not None and r != '':
-            restriction = 'search:"%s"'%(r)
+    def apply_text_search_restriction(self, search):
+        if not search:
+            self.search_restriction.setItemText(1, _('*Current search'))
+            self.search_restriction.setCurrentIndex(0)
         else:
-            restriction = ''
+            self.search_restriction.setCurrentIndex(1)
+            self.search_restriction.setItemText(1, search)
+            self._apply_search_restriction(search)
 
+    def apply_search_restriction(self, i):
+        self.search_restriction.setItemText(1, _('*Current search'))
+        if i == 1:
+            restriction = unicode(self.search.currentText())
+            if not restriction:
+                self.search_restriction.setCurrentIndex(0)
+            else:
+                self.search_restriction.setItemText(1, restriction)
+        else:
+            r = unicode(self.search_restriction.currentText())
+            if r is not None and r != '':
+                restriction = 'search:"%s"'%(r)
+            else:
+                restriction = ''
+        self._apply_search_restriction(restriction)
+
+    def _apply_search_restriction(self, restriction):
         self.saved_search.clear()
         # The order below is important. Set the restriction, force a '' search
         # to apply it, reset the tag browser to take it into account, then set

src/calibre/gui2/tag_view.py

@@ -86,6 +86,7 @@ class TagsView(QTreeView): # {{{
     tag_item_renamed        = pyqtSignal()
     search_item_renamed     = pyqtSignal()
     drag_drop_finished      = pyqtSignal(object)
+    restriction_error       = pyqtSignal()
 
     def __init__(self, parent=None):
         QTreeView.__init__(self, parent=None)
@@ -1117,9 +1118,13 @@ class TagsModel(QAbstractItemModel): # {{{
 
         # Get the categories
         if self.search_restriction:
-            data = self.db.get_categories(sort=sort,
+            try:
+                data = self.db.get_categories(sort=sort,
                         icon_map=self.category_icon_map,
                         ids=self.db.search('', return_matches=True))
+            except:
+                data = self.db.get_categories(sort=sort, icon_map=self.category_icon_map)
+                self.tags_view.restriction_error.emit()
         else:
             data = self.db.get_categories(sort=sort, icon_map=self.category_icon_map)
 
@@ -1822,9 +1827,15 @@ class TagBrowserMixin(object): # {{{
         self.tags_view.tag_item_renamed.connect(self.do_tag_item_renamed)
         self.tags_view.search_item_renamed.connect(self.saved_searches_changed)
         self.tags_view.drag_drop_finished.connect(self.drag_drop_finished)
+        self.tags_view.restriction_error.connect(self.do_restriction_error,
+                                                 type=Qt.QueuedConnection)
         self.edit_categories.clicked.connect(lambda x:
                 self.do_edit_user_categories())
 
+    def do_restriction_error(self):
+        error_dialog(self.tags_view, _('Invalid search restriction'),
+                         _('The current search restriction is invalid'), show=True)
+
     def do_add_subcategory(self, on_category_key, new_category_name=None):
         '''
         Add a subcategory to the category 'on_category'. If new_category_name is