From 8df1a9c8cb71e6667cd63a4100f2f6caf96cde4c Mon Sep 17 00:00:00 2001
From: Serge Camille <sergecamille@gmail.com>
Date: Mon, 4 Oct 2021 18:53:13 +0200
Subject: [PATCH 1/2] Add unit test for ReadClass uint32 bug.

https://github.com/S7NetPlus/s7netplus/issues/414
---
 S7.Net.UnitTest/TypeTests/ClassTests.cs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/S7.Net.UnitTest/TypeTests/ClassTests.cs b/S7.Net.UnitTest/TypeTests/ClassTests.cs
index ba99c2cc..03cbe449 100644
--- a/S7.Net.UnitTest/TypeTests/ClassTests.cs
+++ b/S7.Net.UnitTest/TypeTests/ClassTests.cs
@@ -17,6 +17,19 @@ public void GetClassSizeTest()
             Assert.AreEqual(Class.GetClassSize(new TestClassUnevenSize(3, 17)), 10);
         }
 
+        /// <summary>
+        /// Ensure Uint32 is correctly parsed through ReadClass functions. Adresses issue https://github.com/S7NetPlus/s7netplus/issues/414
+        /// </summary>
+        [TestMethod]
+        public void TestUint32Read()
+        {
+            var result = new TestUint32();
+            var data = new byte[4] { 0, 0, 0, 5 };
+            var bytesRead = Class.FromBytes(result, data);
+            Assert.AreEqual(bytesRead, data.Length);
+            Assert.AreEqual(5u, result.Value1);
+        }
+
         private class TestClassUnevenSize
         {
             public bool Bool { get; set; }
@@ -29,5 +42,10 @@ public TestClassUnevenSize(int byteCount, int bitCount)
                 Bools = new bool[bitCount];
             }
         }
+
+        private class TestUint32
+        {
+            public uint Value1 { get; set; }
+        }
     }
 }

From 12281ec8020dfad274a84ece094eee60ef5b4940 Mon Sep 17 00:00:00 2001
From: Serge Camille <sergecamille@gmail.com>
Date: Mon, 4 Oct 2021 18:59:05 +0200
Subject: [PATCH 2/2] Fix ReadClass for Uint32

Use consistent DWord conversion for both Int32 and UInt32. Unfortunately there is no Span or even a FromByteArray function accepting a offset, so just use the same Array.Copy falls used for double.
---
 S7.Net/Types/Class.cs | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/S7.Net/Types/Class.cs b/S7.Net/Types/Class.cs
index 0dd78fa3..225f3f8c 100644
--- a/S7.Net/Types/Class.cs
+++ b/S7.Net/Types/Class.cs
@@ -153,11 +153,9 @@ public static double GetClassSize(object instance, double numBytes = 0.0, bool i
                     numBytes = Math.Ceiling(numBytes);
                     if ((numBytes / 2 - Math.Floor(numBytes / 2.0)) > 0)
                         numBytes++;
-                    // hier auswerten
-                    uint sourceUInt = DWord.FromBytes(bytes[(int)numBytes + 3],
-                                                                       bytes[(int)numBytes + 2],
-                                                                       bytes[(int)numBytes + 1],
-                                                                       bytes[(int)numBytes + 0]);
+                    var wordBuffer = new byte[4];
+                    Array.Copy(bytes, (int)numBytes, wordBuffer, 0, wordBuffer.Length);
+                    uint sourceUInt = DWord.FromByteArray(wordBuffer);
                     value = sourceUInt.ConvertToInt();
                     numBytes += 4;
                     break;
@@ -165,12 +163,9 @@ public static double GetClassSize(object instance, double numBytes = 0.0, bool i
                     numBytes = Math.Ceiling(numBytes);
                     if ((numBytes / 2 - Math.Floor(numBytes / 2.0)) > 0)
                         numBytes++;
-                    // hier auswerten
-                    value = DWord.FromBytes(
-                        bytes[(int)numBytes],
-                        bytes[(int)numBytes + 1],
-                        bytes[(int)numBytes + 2],
-                        bytes[(int)numBytes + 3]);
+                    var wordBuffer2 = new byte[4];
+                    Array.Copy(bytes, (int)numBytes, wordBuffer2, 0, wordBuffer2.Length);
+                    value = DWord.FromByteArray(wordBuffer2);
                     numBytes += 4;
                     break;
                 case "Single":