From b857b2a16c2dee9c2e2733dd72508bdd62b1d129 Mon Sep 17 00:00:00 2001
From: Hugh Bellamy <hughbellars@gmail.com>
Date: Tue, 19 Sep 2017 22:28:44 +0100
Subject: [PATCH] Fix multiplying TextureBrush with a disposed matrix on Unix
 (dotnet/corefx#24109)

* Fix multiplying TextureBrush with a disposed matrix on Unix

* Enable another passing test

* Fix accidentally committed file


Commit migrated from https://github.com/dotnet/corefx/commit/15f9a31fd45f9a7d667765ef08ecfd1cefddde3a
---
 .../src/System/Drawing/TextureBrush.cs                   | 9 ++++++++-
 .../System.Drawing.Common/tests/TextureBrushTests.cs     | 4 ----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/libraries/System.Drawing.Common/src/System/Drawing/TextureBrush.cs b/src/libraries/System.Drawing.Common/src/System/Drawing/TextureBrush.cs
index c39f329afc107..1710dfb4dc43b 100644
--- a/src/libraries/System.Drawing.Common/src/System/Drawing/TextureBrush.cs
+++ b/src/libraries/System.Drawing.Common/src/System/Drawing/TextureBrush.cs
@@ -168,7 +168,7 @@ public Matrix Transform
             {
                 if (value == null)
                 {
-                    throw new ArgumentNullException("value");
+                    throw new ArgumentNullException(nameof(value));
                 }
 
                 int status = SafeNativeMethods.Gdip.GdipSetTextureTransform(new HandleRef(this, NativeBrush), new HandleRef(value, value.nativeMatrix));
@@ -225,6 +225,13 @@ public void MultiplyTransform(Matrix matrix, MatrixOrder order)
                 throw new ArgumentNullException(nameof(matrix));
             }
 
+            // Multiplying the transform by a disposed matrix is a nop in GDI+, but throws
+            // with the libgdiplus backend. Simulate a nop for compatability with GDI+.
+            if (matrix.nativeMatrix == IntPtr.Zero)
+            {
+                return;
+            }
+
             int status = SafeNativeMethods.Gdip.GdipMultiplyTextureTransform(new HandleRef(this, NativeBrush),
                                                               new HandleRef(matrix, matrix.nativeMatrix),
                                                               order);
diff --git a/src/libraries/System.Drawing.Common/tests/TextureBrushTests.cs b/src/libraries/System.Drawing.Common/tests/TextureBrushTests.cs
index bb93324f0d0ac..02e3e4cc39160 100644
--- a/src/libraries/System.Drawing.Common/tests/TextureBrushTests.cs
+++ b/src/libraries/System.Drawing.Common/tests/TextureBrushTests.cs
@@ -294,7 +294,6 @@ public void Ctor_DisposedImage_ThrowsArgumentException()
             AssertExtensions.Throws<ArgumentException>(null, () => new TextureBrush(image, WrapMode.Tile, Rectangle.Empty));
         }
 
-        [ActiveIssue(20884, TestPlatforms.AnyUnix)]
         [ConditionalTheory(Helpers.GdiplusIsAvailable)]
         [InlineData(WrapMode.Tile - 1)]
         [InlineData(WrapMode.Clamp + 1)]
@@ -431,7 +430,6 @@ public void MultiplyTransform_NotInvertibleMatrix_ThrowsArgumentException()
             }
         }
 
-        [ActiveIssue(20884, TestPlatforms.AnyUnix)]
         [ConditionalFact(Helpers.GdiplusIsAvailable)]
         public void MultiplyTransform_DisposedMatrix_Nop()
         {
@@ -662,7 +660,6 @@ public void Transform_SetValid_GetReturnsExpected()
             }
         }
 
-        [ActiveIssue(20884, TestPlatforms.AnyUnix)]
         [ConditionalFact(Helpers.GdiplusIsAvailable)]
         public void Transform_SetNull_ThrowsArgumentNullException()
         {
@@ -786,7 +783,6 @@ public void WrapMode_SetValid_GetReturnsExpected(WrapMode wrapMode)
             }
         }
 
-        [ActiveIssue(20884, TestPlatforms.AnyUnix)]
         [ConditionalTheory(Helpers.GdiplusIsAvailable)]
         [InlineData(WrapMode.Tile - 1)]
         [InlineData(WrapMode.Clamp + 1)]