From f2875d86f92c39e8cf1e4a4bb7ac2c5bb000d4b7 Mon Sep 17 00:00:00 2001
From: Matthew Leibowitz <mattleibow@live.com>
Date: Fri, 18 Nov 2016 02:17:27 +0200
Subject: [PATCH] Added an overload for SKData.AsStream that disposes data

---
 binding/Binding/SKData.cs | 50 +++++++++++++++++++++++----------------
 tests/Tests/SKDataTest.cs | 21 ++++++++++++++++
 2 files changed, 51 insertions(+), 20 deletions(-)

diff --git a/binding/Binding/SKData.cs b/binding/Binding/SKData.cs
index 1081b310..5475279e 100644
--- a/binding/Binding/SKData.cs
+++ b/binding/Binding/SKData.cs
@@ -95,29 +95,16 @@ namespace SkiaSharp
 
 		public IntPtr Data => SkiaApi.sk_data_get_data (Handle);
 
-		private unsafe class MyUnmanagedMemoryStream : UnmanagedMemoryStream
-		{
-			private SKData host;
-
-			public MyUnmanagedMemoryStream (SKData host)
-				: base((byte *) host.Data, host.Size)
-			{
-				this.host = host;
-			}
-
-			protected override void Dispose (bool disposing)
-			{
-				base.Dispose (disposing);
-
-				host = null;
-			}
-		}
-		
 		public Stream AsStream ()
 		{
-			return new MyUnmanagedMemoryStream (this);
+			return new SKDataStream (this, false);
 		}
-		
+
+		public Stream AsStream (bool streamDisposesData)
+		{
+			return new SKDataStream (this, streamDisposesData);
+		}
+
 		public void SaveTo (Stream target)
 		{
 			if (target == null)
@@ -135,6 +122,29 @@ namespace SkiaSharp
 				target.Write (buffer, 0, copyCount);
 			}
 		}
+
+		private class SKDataStream : UnmanagedMemoryStream
+		{
+			private SKData host;
+			private readonly bool disposeHost;
+
+			public unsafe SKDataStream (SKData host, bool disposeHost = false)
+				: base((byte *) host.Data, host.Size)
+			{
+				this.host = host;
+				this.disposeHost = disposeHost;
+			}
+
+			protected override void Dispose (bool disposing)
+			{
+				base.Dispose (disposing);
+
+				if (disposeHost) {
+					host?.Dispose ();
+				}
+				host = null;
+			}
+		}
 	}
 }
 
diff --git a/tests/Tests/SKDataTest.cs b/tests/Tests/SKDataTest.cs
index d8f990b7..ac62b8d6 100644
--- a/tests/Tests/SKDataTest.cs
+++ b/tests/Tests/SKDataTest.cs
@@ -17,5 +17,26 @@ namespace SkiaSharp.Tests
 			Assert.AreEqual(OddData.Length, data.Size);
 			CollectionAssert.AreEqual(OddData, data.ToArray());
 		}
+
+		[Test]
+		public void DataDisposedReturnsInvalidStream()
+		{
+			// create data
+			var data = new SKData(OddData);
+
+			// get the stream
+			var stream = data.AsStream();
+
+			// nuke the data
+			data.Dispose();
+			Assert.AreEqual(IntPtr.Zero, data.Handle);
+
+			// read the stream
+			var buffer = new byte[OddData.Length];
+			stream.Read(buffer, 0, buffer.Length);
+
+			// since the data was nuked, they will differ
+			CollectionAssert.AreNotEqual(OddData, buffer);
+		}
 	}
 }