From d7386a93fea9446c2554873f8d6bd175824722e5 Mon Sep 17 00:00:00 2001
From: Carlos Fernandez <cfern1990@gmail.com>
Date: Fri, 6 Mar 2026 00:24:19 -0500
Subject: [PATCH] Also migrate sub fields of MappingField

---
 module/data/fields/mappingField.mjs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/module/data/fields/mappingField.mjs b/module/data/fields/mappingField.mjs
index 31d91c76..05f07467 100644
--- a/module/data/fields/mappingField.mjs
+++ b/module/data/fields/mappingField.mjs
@@ -125,4 +125,14 @@ export default class MappingField extends foundry.data.fields.ObjectField {
         path.shift();
         return this.model._getField(path);
     }
+
+    /* -------------------------------------------- */
+
+    migrateSource(sourceData, fieldData) {
+        for (const key of Object.keys(fieldData)) {
+            const isDeletion = foundry.utils.isDeletionKey(key);
+            if (isDeletion && key[0] === '-') continue;
+            this.model.migrateSource(sourceData, fieldData[key]);
+        }
+    }
 }