Added failing test for #3041.

tests/Avalonia.Layout.UnitTests/LayoutManagerTests.cs

@@ -341,5 +341,38 @@ namespace Avalonia.Layout.UnitTests
             //layoutmanager should process properly other visuals
             Assert.All(targets, c => Assert.True(c.Arranged));
         }
+
+
+        [Fact]
+        public void LayoutManager_Should_Recover_From_Infinite_Loop_On_Measure()
+        {
+            // Test for issue #3041.
+            var control = new LayoutTestControl();
+            var root = new LayoutTestRoot { Child = control };
+
+            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            control.Measured = false;
+
+            control.DoMeasureOverride = (l, s) =>
+            {
+                control.InvalidateMeasure();
+                return new Size(100, 100);
+            };
+
+            control.InvalidateMeasure();
+            root.LayoutManager.ExecuteLayoutPass();
+
+            // This is the important part: running a second layout pass in which we exceed the maximum
+            // retries causes LayoutQueue<T>.Info.Count to exceed _maxEnqueueCountPerLoop.
+            root.LayoutManager.ExecuteLayoutPass();
+
+            control.Measured = false;
+            control.DoMeasureOverride = null;
+
+            root.LayoutManager.ExecuteLayoutPass();
+
+            Assert.True(control.Measured);
+            Assert.True(control.IsMeasureValid);
+        }
     }
 }