From c03cd7c26e89ab3307902d19fa97d529fa17a8c7 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 21 Oct 2025 19:59:09 +0000
Subject: [PATCH 1/3] Initial plan


From 70b9a1fae9fc987066feeb20a84cc2e87c865c3b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 21 Oct 2025 20:16:35 +0000
Subject: [PATCH 2/3] Fix: Prevent overridden PageModel lifecycle methods from
 being discovered as handlers

Co-authored-by: MackinnonBuck <10456961+MackinnonBuck@users.noreply.github.com>
---
 ...efaultPageApplicationModelPartsProvider.cs |  4 +-
 ...DefaultPageApplicationModelProviderTest.cs | 47 +++++++++++++++++++
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/src/Mvc/Mvc.RazorPages/src/ApplicationModels/DefaultPageApplicationModelPartsProvider.cs b/src/Mvc/Mvc.RazorPages/src/ApplicationModels/DefaultPageApplicationModelPartsProvider.cs
index 5de6835aefa6..9b7ccb1284ec 100644
--- a/src/Mvc/Mvc.RazorPages/src/ApplicationModels/DefaultPageApplicationModelPartsProvider.cs
+++ b/src/Mvc/Mvc.RazorPages/src/ApplicationModels/DefaultPageApplicationModelPartsProvider.cs
@@ -199,8 +199,8 @@ public bool IsHandler(MethodInfo methodInfo)
             return false;
         }
 
-        // Exclude methods declared on PageModel
-        if (declaringType == typeof(PageModel))
+        // Exclude methods declared on PageModel (including overrides)
+        if (methodInfo.GetBaseDefinition().DeclaringType == typeof(PageModel))
         {
             return false;
         }
diff --git a/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs b/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs
index 7d304f7c0a05..8a7221100e9f 100644
--- a/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs
+++ b/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs
@@ -1214,6 +1214,53 @@ public void PopulateFilters_AddsPageHandlerPageFilter_ForModelDerivingFromTypeIm
     [ServiceFilter(typeof(IServiceProvider))]
     private class DerivedFromPageModel : PageModel { }
 
+    [Fact]
+    public void PopulateHandlerMethods_Ignores_OverriddenPageModelLifecycleMethods()
+    {
+        // Arrange
+        var provider = CreateProvider();
+        var typeInfo = typeof(ModelOverridingPageModelLifecycle).GetTypeInfo();
+        var pageModel = new PageApplicationModel(new PageActionDescriptor(), typeInfo, new object[0]);
+
+        // Act
+        provider.PopulateHandlerMethods(pageModel);
+
+        // Assert
+        // Only OnGet should be discovered as a handler. OnPageHandlerExecuting, OnPageHandlerExecuted,
+        // and OnPageHandlerSelected are lifecycle methods and should be excluded even when overridden.
+        var handlerMethods = pageModel.HandlerMethods;
+        Assert.Collection(
+            handlerMethods,
+            handler =>
+            {
+                Assert.Equal(nameof(ModelOverridingPageModelLifecycle.OnGet), handler.MethodInfo.Name);
+                Assert.Equal("Get", handler.HttpMethod);
+                Assert.Null(handler.HandlerName);
+            });
+    }
+
+    private class ModelOverridingPageModelLifecycle : PageModel
+    {
+        public void OnGet()
+        {
+        }
+
+        public override void OnPageHandlerExecuting(PageHandlerExecutingContext context)
+        {
+            base.OnPageHandlerExecuting(context);
+        }
+
+        public override void OnPageHandlerExecuted(PageHandlerExecutedContext context)
+        {
+            base.OnPageHandlerExecuted(context);
+        }
+
+        public override void OnPageHandlerSelected(PageHandlerSelectedContext context)
+        {
+            base.OnPageHandlerSelected(context);
+        }
+    }
+
     private static DefaultPageApplicationModelProvider CreateProvider()
     {
         var modelMetadataProvider = TestModelMetadataProvider.CreateDefaultProvider();

From 17481917b48993cac9dd646d3f444462af128e48 Mon Sep 17 00:00:00 2001
From: Mackinnon Buck <mackinnon.buck@gmail.com>
Date: Wed, 22 Oct 2025 09:59:52 -0700
Subject: [PATCH 3/3] Update
 src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs

---
 .../DefaultPageApplicationModelProviderTest.cs                  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs b/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs
index 8a7221100e9f..e485da7156c6 100644
--- a/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs
+++ b/src/Mvc/Mvc.RazorPages/test/ApplicationModels/DefaultPageApplicationModelProviderTest.cs
@@ -1220,7 +1220,7 @@ public void PopulateHandlerMethods_Ignores_OverriddenPageModelLifecycleMethods()
         // Arrange
         var provider = CreateProvider();
         var typeInfo = typeof(ModelOverridingPageModelLifecycle).GetTypeInfo();
-        var pageModel = new PageApplicationModel(new PageActionDescriptor(), typeInfo, new object[0]);
+        var pageModel = new PageApplicationModel(new PageActionDescriptor(), typeInfo, []);
 
         // Act
         provider.PopulateHandlerMethods(pageModel);