From cc7170875fc9def8c2e633f4b4d1dfc310da8744 Mon Sep 17 00:00:00 2001
From: dahall <dahall@byu.net>
Date: Fri, 17 Jan 2020 07:54:15 -0700
Subject: [PATCH] Fix and test for #101 - Bug when using SafeAnysizeStruct.

---
 PInvoke/Shared/InteropServices/SafeAnysizeStruct.cs            | 6 +++---
 UnitTests/PInvoke/Shared/InteropServices/AnysizeStructTests.cs | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/PInvoke/Shared/InteropServices/SafeAnysizeStruct.cs b/PInvoke/Shared/InteropServices/SafeAnysizeStruct.cs
index 5eb3b38b..e94a28ac 100644
--- a/PInvoke/Shared/InteropServices/SafeAnysizeStruct.cs
+++ b/PInvoke/Shared/InteropServices/SafeAnysizeStruct.cs
@@ -123,9 +123,9 @@ namespace Vanara.InteropServices
 			Size = memSz;
 			// Marshal base structure - don't use Write to prevent loops
 			Marshal.StructureToPtr(value, handle, false);
-			// Push each element of the array into memory
-			for (var i = 0; i < arrLen; i++)
-				handle.Write(((Array)arrVal).GetValue(i), baseSz - arrElemSz * (i - 1), memSz);
+			// Push each element of the array into memory, starting with second item in array since first was pushed by StructureToPtr
+			for (var i = 1; i < arrLen; i++)
+				handle.Write(((Array)arrVal).GetValue(i), baseSz + arrElemSz * (i - 1), memSz);
 		}
 	}
 
diff --git a/UnitTests/PInvoke/Shared/InteropServices/AnysizeStructTests.cs b/UnitTests/PInvoke/Shared/InteropServices/AnysizeStructTests.cs
index be7ffaf0..f1443626 100644
--- a/UnitTests/PInvoke/Shared/InteropServices/AnysizeStructTests.cs
+++ b/UnitTests/PInvoke/Shared/InteropServices/AnysizeStructTests.cs
@@ -29,7 +29,7 @@ namespace Vanara.InteropServices.Tests
 		[Test]
 		public void ConvertTest()
 		{
-			var array = new[] { long.MinValue, 0L, long.MaxValue };
+			var array = new[] { long.MinValue, 1L, long.MaxValue };
 			var ts = new TestStruct { iVal = array.Length, array = array };
 
 			using var mem = new SafeAnysizeStruct<TestStruct>(ts);