From f28edd3855101fca4703c98f442c44a6e8681590 Mon Sep 17 00:00:00 2001
From: Andriy Svyryd <Andriy.Svyryd@microsoft.com>
Date: Tue, 12 Jan 2021 17:01:47 -0800
Subject: [PATCH] Add quirk mode for #23792

---
 .../Migrations/Internal/MigrationsModelDiffer.cs               | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs b/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
index 6410c946a1b..21ff4789482 100644
--- a/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
+++ b/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
@@ -1898,6 +1898,7 @@ protected virtual Dictionary<IEntityType, List<ITable>> DiffData(
                     principalSourceTable = mainSourceEntityType.GetTableMappings().First().Table;
                 }
 
+                var useOldBehavior = AppContext.TryGetSwitch("Microsoft.EntityFrameworkCore.Issue23792", out var enabled) && enabled;
                 foreach (var sourceSeed in sourceEntityType.GetSeedData())
                 {
                     var sourceEntry = GetEntry(sourceSeed, sourceEntityType, _sourceUpdateAdapter);
@@ -1985,7 +1986,7 @@ protected virtual Dictionary<IEntityType, List<ITable>> DiffData(
                             {
                                 if (targetProperty.GetAfterSaveBehavior() != PropertySaveBehavior.Save
                                     && (targetProperty.ValueGenerated & ValueGenerated.OnUpdate) == 0
-                                    && (targetKeyMap.Count == 1 || entry.EntityType.Name == sourceEntityType.Name))
+                                    && (useOldBehavior || targetKeyMap.Count == 1 || entry.EntityType.Name == sourceEntityType.Name))
                                 {
                                     entryMapping.RecreateRow = true;
                                     break;