From 0ef28853fd96c2ec516339c9f6c147003556edac Mon Sep 17 00:00:00 2001
From: Damien Elmes <gpg@ankiweb.net>
Date: Sat, 30 Sep 2023 15:38:11 +1000
Subject: [PATCH] Fix TypeError when deck list or overview refreshes during
 optimal retention

Caused by legacy code blocking the main thread.

https://forums.ankiweb.net/t/anki-23-10-beta/34912/79
---
 pylib/anki/scheduler/dummy.py |  4 ++--
 qt/aqt/deckbrowser.py         | 19 ++++++++++++++-----
 qt/aqt/overview.py            | 18 ++++++++++++------
 3 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/pylib/anki/scheduler/dummy.py b/pylib/anki/scheduler/dummy.py
index 283d702bc..5732ad346 100644
--- a/pylib/anki/scheduler/dummy.py
+++ b/pylib/anki/scheduler/dummy.py
@@ -29,5 +29,5 @@ class DummyScheduler(SchedulerBaseWithLegacy):
     def active_decks(self) -> list[DeckId]:
         return []
 
-    def counts(self) -> list[int]:
-        return [0, 0, 0]
+    def counts(self) -> tuple[int, int, int]:
+        return (0, 0, 0)
diff --git a/qt/aqt/deckbrowser.py b/qt/aqt/deckbrowser.py
index 80a2e13b4..f0b91adfd 100644
--- a/qt/aqt/deckbrowser.py
+++ b/qt/aqt/deckbrowser.py
@@ -146,12 +146,21 @@ class DeckBrowser:
 
     def _renderPage(self, reuse: bool = False) -> None:
         if not reuse:
-            self._dueTree = self.mw.col.sched.deck_due_tree()
-            self.__renderPage(None)
-            return
-        self.web.evalWithCallback("window.pageYOffset", self.__renderPage)
 
-    def __renderPage(self, offset: int) -> None:
+            def success(tree: DeckTreeNode) -> None:
+                self._dueTree = tree
+                self.__renderPage(None)
+                return
+
+            QueryOp(
+                parent=self.mw,
+                op=lambda col: col.sched.deck_due_tree(),
+                success=success,
+            ).run_in_background()
+        else:
+            self.web.evalWithCallback("window.pageYOffset", self.__renderPage)
+
+    def __renderPage(self, offset: int | None) -> None:
         content = DeckBrowserContent(
             tree=self._renderDeckTree(self._dueTree),
             stats=self._renderStats(),
diff --git a/qt/aqt/overview.py b/qt/aqt/overview.py
index 9d64b0db6..97251775d 100644
--- a/qt/aqt/overview.py
+++ b/qt/aqt/overview.py
@@ -12,6 +12,7 @@ from anki.scheduler import UnburyDeck
 from aqt import gui_hooks
 from aqt.deckdescription import DeckDescriptionDialog
 from aqt.deckoptions import display_options_for_deck
+from aqt.operations import QueryOp
 from aqt.operations.scheduling import (
     empty_filtered_deck,
     rebuild_filtered_deck,
@@ -61,12 +62,17 @@ class Overview:
         self.refresh()
 
     def refresh(self) -> None:
-        self._refresh_needed = False
-        self.mw.col.reset()
-        self._renderPage()
-        self._renderBottom()
-        self.mw.web.setFocus()
-        gui_hooks.overview_did_refresh(self)
+        def success(_counts: tuple) -> None:
+            self._refresh_needed = False
+            self.mw.col.reset()
+            self._renderPage()
+            self._renderBottom()
+            self.mw.web.setFocus()
+            gui_hooks.overview_did_refresh(self)
+
+        QueryOp(
+            parent=self.mw, op=lambda col: col.sched.counts(), success=success
+        ).run_in_background()
 
     def refresh_if_needed(self) -> None:
         if self._refresh_needed: