fix backup not being taken before full download

qt/aqt/main.py

@@ -557,6 +557,13 @@ class AnkiQt(QMainWindow):
         if not corrupt and not self.restoringBackup:
             self.backup()
 
+    def _close_for_full_download(self) -> None:
+        "Backup and prepare collection to be overwritten."
+        self.col.close(downgrade=False)
+        self.backup()
+        self.col.reopen(after_full_sync=False)
+        self.col.close_for_full_sync()
+
     # Backup and auto-optimize
     ##########################################################################
 
@@ -577,6 +584,9 @@ class AnkiQt(QMainWindow):
             z.close()
 
     def backup(self) -> None:
+        "Read data into memory, and complete backup on a background thread."
+        assert not self.col or not self.col.db
+
         nbacks = self.pm.profile["numBackups"]
         if not nbacks or devMode:
             return
@@ -607,7 +617,8 @@ class AnkiQt(QMainWindow):
             fname = backups.pop(0)
             path = os.path.join(dir, fname)
             os.unlink(path)
-        gui_hooks.backup_did_complete()
+
+        self.taskman.run_on_main(gui_hooks.backup_did_complete)
 
     def maybeOptimize(self) -> None:
         # have two weeks passed?

qt/aqt/sync.py

@@ -172,16 +172,18 @@ def on_full_sync_timer(mw: aqt.main.AnkiQt) -> None:
 
 
 def full_download(mw: aqt.main.AnkiQt, on_done: Callable[[], None]) -> None:
-    mw.col.close_for_full_sync()
-
-    def on_timer():
+    def on_timer() -> None:
         on_full_sync_timer(mw)
 
     timer = QTimer(mw)
     qconnect(timer.timeout, on_timer)
     timer.start(150)
 
-    def on_future_done(fut):
+    def download() -> None:
+        mw._close_for_full_download()
+        mw.col.backend.full_download(mw.pm.sync_auth())
+
+    def on_future_done(fut) -> None:
         timer.stop()
         mw.col.reopen(after_full_sync=True)
         mw.reset()
@@ -193,7 +195,7 @@ def full_download(mw: aqt.main.AnkiQt, on_done: Callable[[], None]) -> None:
         return on_done()
 
     mw.taskman.with_progress(
-        lambda: mw.col.backend.full_download(mw.pm.sync_auth()),
+        download,
         on_future_done,
         label=tr(TR.SYNC_DOWNLOADING_FROM_ANKIWEB),
     )