1) Fix problem with case sensitive matching when creating user categories

2) Fix problem in search where setting focus to the search box then removing it caused the item in history to replace the item in the search box case-insensitively. This broke tag state matching in the tag browser.

src/calibre/gui2/dialogs/tag_categories.py

@@ -178,8 +178,10 @@ class TagCategories(QDialog, Ui_TagCategories):
                       'multiple periods in a row or spaces before '
                       'or after periods.')).exec_()
             return False
-        for c in self.categories:
+        for c in sorted(self.categories.keys(), key=sort_key):
-            if strcmp(c, cat_name) == 0:
+            if strcmp(c, cat_name) == 0 or \
+                    (icu_lower(cat_name).startswith(icu_lower(c) + '.') and\
+                     not cat_name.startswith(c + '.')):
                 error_dialog(self, _('Name already used'),
                         _('That name is already used, perhaps with different case.')).exec_()
                 return False

src/calibre/gui2/search_box.py

@@ -217,11 +217,15 @@ class SearchBox2(QComboBox): # {{{
                 self.clear()
             else:
                 self.normalize_state()
+                self.lineEdit().setCompleter(None)
                 self.setEditText(txt)
                 self.line_edit.end(False)
                 if emit_changed:
                     self.changed.emit()
                 self._do_search(store_in_history=store_in_history)
+                c = QCompleter()
+                self.lineEdit().setCompleter(c)
+                c.setCompletionMode(c.PopupCompletion)
             self.focus_to_library.emit()
         finally:
             if not store_in_history:

src/calibre/gui2/tag_view.py

@@ -654,7 +654,6 @@ class TagTreeItem(object): # {{{
         '''
         set_to: None => advance the state, otherwise a value from TAG_SEARCH_STATES
         '''
-#        if self.type == self.TAG:
         if set_to is None:
             while True:
                 self.tag.state = (self.tag.state + 1)%5
@@ -1319,16 +1318,19 @@ class TagsModel(QAbstractItemModel): # {{{
                 return False
 
             user_cats = self.db.prefs.get('user_categories', {})
+            user_cat_keys_lower = [icu_lower(k) for k in user_cats]
             ckey = item.category_key[1:]
+            ckey_lower = icu_lower(ckey)
             dotpos = ckey.rfind('.')
             if dotpos < 0:
                 nkey = val
             else:
                 nkey = ckey[:dotpos+1] + val
-            for c in user_cats:
+            nkey_lower = icu_lower(nkey)
-                if c.startswith(ckey):
+            for c in sorted(user_cats.keys(), key=sort_key):
+                if icu_lower(c).startswith(ckey_lower):
                     if len(c) == len(ckey):
-                        if nkey in user_cats:
+                        if nkey_lower in user_cat_keys_lower:
                             error_dialog(self.tags_view, _('Rename user category'),
                                 _('The name %s is already used')%nkey, show=True)
                             return False
@@ -1336,7 +1338,7 @@ class TagsModel(QAbstractItemModel): # {{{
                         del user_cats[ckey]
                     elif c[len(ckey)] == '.':
                         rest = c[len(ckey):]
-                        if (nkey + rest) in user_cats:
+                        if icu_lower(nkey + rest) in user_cat_keys_lower:
                             error_dialog(self.tags_view, _('Rename user category'),
                                 _('The name %s is already used')%(nkey+rest), show=True)
                             return False
@@ -1512,7 +1514,6 @@ class TagsModel(QAbstractItemModel): # {{{
     def reset_all_states(self, except_=None):
         update_list = []
         def process_tag(tag_item):
-#            if tag_item.type != TagTreeItem.CATEGORY:
             tag = tag_item.tag
             if tag is except_:
                 tag_index = self.createIndex(tag_item.row(), 0, tag_item)