Hex Editor - fix issue 150 - exceptions thrown when freezing multi-byte addresses

BizHawk.Client.Common/tools/Cheat.cs

@@ -243,6 +243,44 @@ namespace BizHawk.Client.Common
 			}
 		}
 
+		public byte? GetByteVal(int addr)
+		{
+			if (!Contains(addr))
+			{
+				return null;
+			}
+
+			switch (_watch.Size)
+			{
+				default:
+				case Watch.WatchSize.Separator:
+				case Watch.WatchSize.Byte:
+					return (byte?)_val;
+				case Watch.WatchSize.Word:
+					if (addr == (_watch.Address ?? 0))
+					{
+						return (byte)(_val >> 8);
+					}
+
+					return (byte)(_val & 0xFF);
+				case Watch.WatchSize.DWord:
+					if (addr == (_watch.Address ?? 0))
+					{
+						return (byte)((_val >> 24) & 0xFF);
+					}
+					else if (addr == (_watch.Address ?? 0) + 1)
+					{
+						return (byte)((_val >> 16) & 0xFF);
+					}
+					else if (addr == ((_watch.Address ?? 0)) + 2)
+					{
+						return (byte)((_val >> 8) & 0xFF);
+					}
+
+					return (byte)(_val & 0xFF);
+			}
+		}
+
 		public void Increment()
 		{
 			if (!IsSeparator)

BizHawk.Client.Common/tools/CheatList.cs

@@ -240,6 +240,22 @@ namespace BizHawk.Client.Common
 					&& cheat.Contains(address));
 		}
 
+		/// <summary>
+		/// Returns the value of a given byte in a cheat, If the cheat is a single byte this will be the same indexing the cheat,
+		/// But if the cheat is multi-byte, this will return just the cheat value for that specific byte
+		/// </summary>
+		/// <returns>Returns null if address is not a part of a cheat, else returns the value of that specific byte only</returns>
+		public byte? GetByteValue(MemoryDomain domain, int addr)
+		{
+			var activeCheat = _cheatList.FirstOrDefault(cheat => cheat.Contains(addr));
+			if (activeCheat == (Cheat)null)
+			{
+				return null;
+			}
+
+			return activeCheat.GetByteVal(addr);
+		}
+
 		public void SaveOnClose()
 		{
 			if (Global.Config.CheatsAutoSaveOnClose)

BizHawk.Client.EmuHawk/tools/HexEditor/HexEditor.cs

@@ -560,7 +560,7 @@ namespace BizHawk.Client.EmuHawk
 		private byte MakeByte(int address)
 		{
 			return Global.CheatList.IsActive(_domain, address)
-				? (byte) Global.CheatList[_domain, address].Value.Value
+				? Global.CheatList.GetByteValue(_domain, address).Value
 				: _domain.PeekByte(address); 
 		}