From 16b0cb864d147a82c050e662aa2be8249f788962 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C4=B0lker=20amca?= <ilkertskn@gmail.com>
Date: Fri, 31 Jul 2026 00:32:57 +0300
Subject: [PATCH] Emit oldStored based on the old column in
 CSharpMigrationOperationGenerator

- The oldStored: argument of a generated AlterColumn call was gated on operation.IsStored (the new
  column) while emitting operation.OldColumn.IsStored, so altering a column away from a stored
  computed column dropped oldStored: from the generated (and reverse) migration
- Gate on operation.OldColumn.IsStored to match the value being written
- Add a test covering alter from a stored computed column to a non-computed column
---
 .../CSharpMigrationOperationGenerator.cs      |  2 +-
 .../CSharpMigrationOperationGeneratorTest.cs  | 31 +++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/EFCore.Design/Migrations/Design/CSharpMigrationOperationGenerator.cs b/src/EFCore.Design/Migrations/Design/CSharpMigrationOperationGenerator.cs
index 9c57eebf295..89af76dcb32 100644
--- a/src/EFCore.Design/Migrations/Design/CSharpMigrationOperationGenerator.cs
+++ b/src/EFCore.Design/Migrations/Design/CSharpMigrationOperationGenerator.cs
@@ -640,7 +640,7 @@ protected virtual void Generate(AlterColumnOperation operation, IndentedStringBu
                     .Append("oldComputedColumnSql: ")
                     .Append(Code.Literal(operation.OldColumn.ComputedColumnSql));
 
-                if (operation.IsStored != null)
+                if (operation.OldColumn.IsStored != null)
                 {
                     builder
                         .AppendLine(",")
diff --git a/test/EFCore.Design.Tests/Migrations/Design/CSharpMigrationOperationGeneratorTest.cs b/test/EFCore.Design.Tests/Migrations/Design/CSharpMigrationOperationGeneratorTest.cs
index 3eb017d6fcf..20728837737 100644
--- a/test/EFCore.Design.Tests/Migrations/Design/CSharpMigrationOperationGeneratorTest.cs
+++ b/test/EFCore.Design.Tests/Migrations/Design/CSharpMigrationOperationGeneratorTest.cs
@@ -633,6 +633,37 @@ public void AlterColumnOperation_all_args()
                 Assert.Equal("Some Collation", o.OldColumn.Collation);
             });
 
+    [Fact]
+    public void AlterColumnOperation_computed_to_non_computed_preserves_oldStored()
+        => Test(
+            new AlterColumnOperation
+            {
+                Name = "Id",
+                Table = "Post",
+                ClrType = typeof(int),
+                OldColumn =
+                {
+                    ComputedColumnSql = "1",
+                    IsStored = true
+                }
+            },
+            """
+mb.AlterColumn<int>(
+    name: "Id",
+    table: "Post",
+    nullable: false,
+    oldComputedColumnSql: "1",
+    oldStored: true);
+""",
+            o =>
+            {
+                Assert.Equal("Id", o.Name);
+                Assert.Equal("Post", o.Table);
+                Assert.Equal(typeof(int), o.ClrType);
+                Assert.Equal("1", o.OldColumn.ComputedColumnSql);
+                Assert.True(o.OldColumn.IsStored);
+            });
+
     [Fact]
     public void AlterColumnOperation_DefaultValueSql()
         => Test(