From a856e3695449c19810cdb8395c5879919d6af3d8 Mon Sep 17 00:00:00 2001
From: Stamina9 <1934687883@qq.com>
Date: Wed, 11 Nov 2026 11:08:53 +0800
Subject: [PATCH] fix(donut): allow returning to a disabled front face

Keep the front reachable after flipping to a usable back face, even
when every front slice is disabled.

Addresses #1374.
---
 src/Filee.App/ViewModels/RadialViewModel.cs |  3 ++-
 tests/Filee.App.Tests/DonutFlipTests.cs     | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/Filee.App/ViewModels/RadialViewModel.cs b/src/Filee.App/ViewModels/RadialViewModel.cs
index cb5043d53..eb8daa732 100644
--- a/src/Filee.App/ViewModels/RadialViewModel.cs
+++ b/src/Filee.App/ViewModels/RadialViewModel.cs
@@ -228,7 +228,8 @@ private void ShowFace(bool back, bool checkBack = true)
             Items = face.Items;
         }
         var other = back ? _front : checkBack ? BackFace() : _back;
-        CanFlip = other?.IsUsable == true;
+        // The front was already shown, even when every slice was disabled. Do not strand the user on the back face.
+        CanFlip = back ? _front.Items.Count > 0 : other?.IsUsable == true;
         var how = FlipKey is { } key ? KeyNames.Display(key) : "";
         FlipHint = CanFlip && (FlipKey is not null || FlipWithWheel)
             ? loc.Format(back ? "donut.flip_to_front" : "donut.flip_to_back", how).Trim()
diff --git a/tests/Filee.App.Tests/DonutFlipTests.cs b/tests/Filee.App.Tests/DonutFlipTests.cs
index 324deabf7..76d2c25b5 100644
--- a/tests/Filee.App.Tests/DonutFlipTests.cs
+++ b/tests/Filee.App.Tests/DonutFlipTests.cs
@@ -735,6 +735,24 @@ public void A_donut_without_a_back_face_does_not_flip() => With(animations: true
         window.Close();
     });
 
+    [AvaloniaFact]
+    public void A_disabled_front_face_is_still_reachable_after_flipping_to_a_usable_back() =>
+        With(animations: false, back: ["to-gif"], () =>
+        {
+            Images.PresetIds = ["to-wav"];
+            var (vm, window, donut) = OpenClickMode();
+            try
+            {
+                Assert.All(vm.Items, item => Assert.False(item.IsEnabled));
+                Assert.True(donut.Flip());
+                Assert.True(vm.IsBackFace);
+                Assert.True(vm.CanFlip);
+                Assert.True(donut.Flip());
+                Assert.False(vm.IsBackFace);
+            }
+            finally { window.Close(); }
+        });
+
     [AvaloniaFact]
     public void The_back_face_greys_out_what_cannot_convert_the_files_and_one_with_nothing_left_does_not_flip()
     {