From 0d2e46feb58c5bdbf5ed5254cc673db39c0043fa Mon Sep 17 00:00:00 2001
From: Damien Elmes <gpg@ankiweb.net>
Date: Sat, 13 Aug 2022 12:05:05 +1000
Subject: [PATCH] Legacy undo & v2 queues must be cleared on backend op

Fixes #12007
---
 AnkiDroid/src/main/java/com/ichi2/libanki/ChangeManager.kt | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/AnkiDroid/src/main/java/com/ichi2/libanki/ChangeManager.kt b/AnkiDroid/src/main/java/com/ichi2/libanki/ChangeManager.kt
index dea1e800b2e3..f57c37220396 100644
--- a/AnkiDroid/src/main/java/com/ichi2/libanki/ChangeManager.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/libanki/ChangeManager.kt
@@ -93,7 +93,12 @@ object ChangeManager {
  * to notify change subscribers of the changes. */
 suspend fun <T> undoableOp(handler: Any? = null, block: CollectionV16.() -> T): T {
     return withCol {
-        this.newBackend.block()
+        val result = newBackend.block()
+        // any backend operation clears legacy undo and resets study queues if it
+        // succeeds
+        clearUndo()
+        reset()
+        result
     }.also {
         withContext(Dispatchers.Main) {
             ChangeManager.notifySubscribers(it, handler)