From 5183fc53addf6741f4c31b27e9f13f1e0ad16a5e Mon Sep 17 00:00:00 2001
From: wisp3rwind <17089248+wisp3rwind@users.noreply.github.com>
Date: Thu, 18 Mar 2021 12:29:39 +0100
Subject: [PATCH] when iterating over item keys, do not return duplicates

... for keys that exist both as Item and Album fields
---
 beets/library.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/beets/library.py b/beets/library.py
index 3ba79d069..00cf00c79 100644
--- a/beets/library.py
+++ b/beets/library.py
@@ -623,7 +623,9 @@ class Item(LibModel):
         """
         keys = super(Item, self).keys(computed=computed)
         if with_album and self._cached_album:
-            keys += self._cached_album.keys(computed=computed)
+            keys = set(keys)
+            keys.update(self._cached_album.keys(computed=computed))
+            keys = list(keys)
         return keys
 
     def get(self, key, default=None, with_album=True):