Use default flag name when flag is renamed to empty string (#3826)

* Add function to restore the default name of a flag

* Call function to restore default flag name if flag renamed to empty string

* Update _load_flags to use the default_flag_names dict

* Add name to contributors file

* Add trailing comma to pass tests

* Update to follow python style guide

* Update about.py

* Revert "Update _load_flags to use the default_flag_names dict"

This reverts commit caa8fea94b.

* Use require_refresh() instead of storing default flag names

CONTRIBUTORS

@@ -213,6 +213,7 @@ wackbyte <wackbyte@protonmail.com>
 GithubAnon0000 <GithubAnon0000@users.noreply.github.com>
 Mike Hardy <github@mikehardy.net>
 Danika_Dakika <https://github.com/Danika-Dakika>
+Mumtaz Hajjo Alrifai <mumtazrifai@protonmail.com>
 
 ********************
 

qt/aqt/about.py

@@ -214,6 +214,7 @@ def show(mw: aqt.AnkiQt) -> QDialog:
             "Gregory Abrasaldo",
             "Danika_Dakika",
             "Marcelo Vasconcelos",
+            "Mumtaz Hajjo Alrifai",
         )
     )
 

qt/aqt/browser/sidebar/tree.py

@@ -453,7 +453,9 @@ class SidebarTreeView(QTreeView):
 
     def _on_rename(self, item: SidebarItem, text: str) -> bool:
         new_name = text.replace('"', "")
-        if new_name and new_name != item.name:
+        if not new_name and item.item_type == SidebarItemType.FLAG:
+            self.restore_default_flag_name(item)
+        elif new_name and new_name != item.name:
             if item.item_type == SidebarItemType.DECK:
                 self.rename_deck(item, new_name)
             elif item.item_type == SidebarItemType.SAVED_SEARCH:
@@ -1089,6 +1091,10 @@ class SidebarTreeView(QTreeView):
         item.name = new_name
         self.mw.flags.rename_flag(item.id, new_name)
 
+    def restore_default_flag_name(self, item: SidebarItem) -> None:
+        self.mw.flags.restore_default_flag_name(item.id)
+        item.name = self.mw.flags.get_flag(item.id).label
+
     # Decks
     ###########################
 

qt/aqt/flags.py

@@ -55,6 +55,15 @@ class FlagManager:
         self.mw.col.set_config("flagLabels", labels)
         gui_hooks.flag_label_did_change()
 
+    def restore_default_flag_name(self, flag_index: int) -> None:
+        labels = self.mw.col.get_config("flagLabels", {})
+        if str(flag_index) not in labels:
+            return
+        del labels[str(flag_index)]
+        self.mw.col.set_config("flagLabels", labels)
+        self.require_refresh()
+        gui_hooks.flag_label_did_change()
+
     def require_refresh(self) -> None:
         "Discard cached labels."
         self._flags = []