Clear Parent on old image source (#29481)

Author: PureWeen

src/Controls/src/Core/ImageElement.cs

@@ -27,8 +27,12 @@ static void OnImageSourceChanged(BindableObject bindable, object oldValue, objec
 		{
 			var newSource = (ImageSource)newValue;
 			var image = (IImageElement)bindable;
-			if (newSource != null && image != null)
+
+			if (newSource is not null && image is not null)
+			{
 				newSource.SourceChanged += image.OnImageSourceSourceChanged;
+			}
+
 			ImageSourceChanged(bindable, newSource);
 		}
 
@@ -37,8 +41,16 @@ static void OnImageSourceChanging(BindableObject bindable, object oldValue, obje
 			var oldSource = (ImageSource)oldValue;
 			var image = (IImageElement)bindable;
 
-			if (oldSource != null && image != null)
-				oldSource.SourceChanged -= image.OnImageSourceSourceChanged;
+			if (oldSource is not null)
+			{
+				if (image is not null)
+				{
+					oldSource.SourceChanged -= image.OnImageSourceSourceChanged;
+				}
+
+				oldSource.Parent = null;
+			}
+
 			ImageSourceChanging(oldSource);
 		}
 

src/Controls/tests/Core.UnitTests/ImageSourceTests.cs

@@ -167,5 +167,16 @@ public async Task CancelCompletes()
 			await ((IStreamImageSource)imageSource).GetStreamAsync();
 			await imageSource.Cancel(); // This should complete!
 		}
+
+		[Fact]
+		public void SettingNewImageeSourceClearsParentOnOldImageSource()
+		{
+			var image = new Image { Source = "File.png" };
+			var imageSource = image.Source;
+			Assert.Equal(image, imageSource.Parent);
+			image.Source = "File2.png";
+			Assert.Null(imageSource.Parent);
+			Assert.Equal(image, image.Source.Parent);
+		}
 	}
-}
+}