From 5ff83fad08d9b6452351b10098c3337c30570003 Mon Sep 17 00:00:00 2001
From: Damien Elmes <gpg@ankiweb.net>
Date: Mon, 4 May 2020 21:28:55 +1000
Subject: [PATCH] catch attempts to overwrite notetype with older version

---
 rslib/src/notetype/mod.rs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/rslib/src/notetype/mod.rs b/rslib/src/notetype/mod.rs
index db1aaff35..83a4bb905 100644
--- a/rslib/src/notetype/mod.rs
+++ b/rslib/src/notetype/mod.rs
@@ -322,12 +322,11 @@ impl Collection {
     pub fn update_notetype(&mut self, nt: &mut NoteType, preserve_usn: bool) -> Result<()> {
         let existing = self.get_notetype(nt.id)?;
         nt.prepare_for_update(existing.as_ref().map(AsRef::as_ref))?;
-        if !preserve_usn {
-            nt.mtime_secs = TimestampSecs::now();
-            nt.usn = self.usn()?;
-        }
         self.transact(None, |col| {
             if let Some(existing_notetype) = existing {
+                if existing_notetype.mtime_secs > nt.mtime_secs {
+                    return Err(AnkiError::invalid_input("attempt to save stale notetype"));
+                }
                 col.update_notes_for_changed_fields(
                     nt,
                     existing_notetype.fields.len(),
@@ -336,6 +335,11 @@ impl Collection {
                 col.update_cards_for_changed_templates(nt, existing_notetype.templates.len())?;
             }
 
+            if !preserve_usn {
+                nt.mtime_secs = TimestampSecs::now();
+                nt.usn = col.usn()?;
+            }
+
             col.storage.update_notetype_config(&nt)?;
             col.storage.update_notetype_fields(nt.id, &nt.fields)?;
             col.storage