Shouldn't have to expicitly define an empty dictionary for parse.

Addendum to this fix is adding a Nodump output for HashSplit

DATabase/DATabase.cs

@@ -1342,7 +1342,6 @@ Make a selection:
 				DatData datdata = new DatData
 				{
 					OutputFormat = outputFormat,
-					Roms = new Dictionary<string, List<RomData>>(),
 					MergeRoms = false,
 				};
 				datdata = RomManipulation.Parse(filename, 0, 0, datdata, logger, true);
@@ -1372,7 +1371,6 @@ Make a selection:
 					DatData datdata = new DatData
 					{
 						OutputFormat = outputFormat,
-						Roms = new Dictionary<string, List<RomData>>(),
 						MergeRoms = false,
 					};
 					datdata = RomManipulation.Parse(file, 0, 0, datdata, logger, true);
@@ -1429,7 +1427,6 @@ Make a selection:
 				logger.User("Converting " + input);
 				DatData datdata = new DatData
 				{
-					Roms = new Dictionary<string, List<RomData>>(),
 					OutputFormat = OutputFormat.MissFile,
 
 					UseGame = usegame,

DATabase/ExtSplit.cs

@@ -56,13 +56,8 @@ namespace SabreTools
 				Directory.CreateDirectory(_outdir);
 			}
 
-			// Create the initial DatData object
-			DatData datdata = new DatData
-			{
-				Roms = new Dictionary<string, List<RomData>>(),
-			};
-
 			// Load the current DAT to be processed
+			DatData datdata = new DatData();
 			datdata = RomManipulation.Parse(_filename, 0, 0, datdata, _logger);
 
 			// Set all of the appropriate outputs for each of the subsets

DATabase/Import.cs

@@ -399,10 +399,7 @@ namespace SabreTools
 			}
 
 			// Get all roms that are found in the DAT to see what needs to be added
-			DatData datdata = new DatData
-			{
-				Roms = new Dictionary<string, List<RomData>>(),
-			};
+			DatData datdata = new DatData();
 			datdata = RomManipulation.Parse(_filepath, sysid, srcid, datdata, _logger);
 
 			// Sort inputted roms into games

DATabase/MergeDiff.cs

@@ -117,7 +117,6 @@ namespace SabreTools
 				ForcePacking = (_forceunpack ? ForcePacking.Unzip : ForcePacking.None),
 				OutputFormat = (_old ? OutputFormat.ClrMamePro : OutputFormat.Xml),
 				MergeRoms = _dedup,
-				Roms = new Dictionary<string, List<RomData>>(),
 				Type = (_superdat ? "SuperDAT" : ""),
 			};
 			foreach (string input in _inputs)
@@ -145,7 +144,6 @@ namespace SabreTools
 					ForcePacking = (_forceunpack ? ForcePacking.Unzip : ForcePacking.None),
 					OutputFormat = (_old ? OutputFormat.ClrMamePro : OutputFormat.Xml),
 					MergeRoms = _dedup,
-					Roms = new Dictionary<string, List<RomData>>(),
 				};
 				foreach (string key in userData.Roms.Keys)
 				{
@@ -189,7 +187,6 @@ namespace SabreTools
 						ForcePacking = (_forceunpack ? ForcePacking.Unzip : ForcePacking.None),
 						OutputFormat = (_old ? OutputFormat.ClrMamePro : OutputFormat.Xml),
 						MergeRoms = _dedup,
-						Roms = new Dictionary<string, List<RomData>>(),
 					};
 
 					foreach (string key in outerDiffData.Roms.Keys)
@@ -228,7 +225,6 @@ namespace SabreTools
 					ForcePacking = (_forceunpack ? ForcePacking.Unzip : ForcePacking.None),
 					OutputFormat = (_old ? OutputFormat.ClrMamePro : OutputFormat.Xml),
 					MergeRoms = _dedup,
-					Roms = new Dictionary<string, List<RomData>>(),
 				};
 				foreach (string key in userData.Roms.Keys)
 				{
@@ -273,7 +269,6 @@ namespace SabreTools
 						ForcePacking = (_forceunpack ? ForcePacking.Unzip : ForcePacking.None),
 						OutputFormat = (_old ? OutputFormat.ClrMamePro : OutputFormat.Xml),
 						MergeRoms = _dedup,
-						Roms = new Dictionary<string, List<RomData>>(),
 					};
 
 					List<string> keys = userData.Roms.Keys.ToList();

DATabase/TrimMerge.cs

@@ -85,7 +85,6 @@ namespace SabreTools
 		{
 			DatData datdata = new DatData
 			{
-				Roms = new Dictionary<string, List<RomData>>(),
 				ForcePacking = (_forceunpack ? ForcePacking.Unzip : ForcePacking.None),
 				OutputFormat = RomManipulation.GetOutputFormat(filename),
 			};

DATabaseTwo/Generate.cs

@@ -156,7 +156,6 @@ namespace SabreTools
 				ForcePacking = ForcePacking.None,
 				OutputFormat = (_old ? OutputFormat.ClrMamePro : OutputFormat.Xml),
 				MergeRoms = true,
-				Roms = new Dictionary<string, List<RomData>>(),
 			};
 
 			// Now read in all of the files

HashSplit/HashSplit.cs

@@ -145,12 +145,32 @@ namespace SabreTools
 			DatData datdata = new DatData
 			{
 				Description = Path.GetFileNameWithoutExtension(filename),
-				Roms = new Dictionary<string, List<RomData>>(),
 			};
 			datdata = RomManipulation.Parse(filename, 0, 0, datdata, _logger, true);
 
 			// Create each of the respective output DATs
 			_logger.User("Creating and populating new DATs");
+			DatData nodump = new DatData
+			{
+				Name = datdata.Name + " (Nodump)",
+				Description = datdata.Description + " (Nodump)",
+				Category = datdata.Category,
+				Version = datdata.Version,
+				Date = datdata.Date,
+				Author = datdata.Author,
+				Email = datdata.Email,
+				Homepage = datdata.Homepage,
+				Url = datdata.Url,
+				Comment = datdata.Comment,
+				Header = datdata.Header,
+				Type = datdata.Type,
+				ForceMerging = datdata.ForceMerging,
+				ForceNodump = datdata.ForceNodump,
+				ForcePacking = datdata.ForcePacking,
+				OutputFormat = outputFormat,
+				MergeRoms = datdata.MergeRoms,
+				Roms = new Dictionary<string, List<RomData>>(),
+			};
 			DatData sha1 = new DatData
 			{
 				Name = datdata.Name + " (SHA-1)",
@@ -195,8 +215,8 @@ namespace SabreTools
 			};
 			DatData crc = new DatData
 			{
-				Name = datdata.Name + " (CRC and None)",
-				Description = datdata.Description + " (CRC and None)",
+				Name = datdata.Name + " (CRC)",
+				Description = datdata.Description + " (CRC)",
 				Category = datdata.Category,
 				Version = datdata.Version,
 				Date = datdata.Date,
@@ -222,8 +242,22 @@ namespace SabreTools
 				List<RomData> roms = datdata.Roms[key];
 				foreach (RomData rom in roms)
 				{
+					// If the file is a nodump
+					if (rom.Nodump)
+					{
+						if (nodump.Roms.ContainsKey(key))
+						{
+							nodump.Roms[key].Add(rom);
+						}
+						else
+						{
+							List<RomData> temp = new List<RomData>();
+							temp.Add(rom);
+							nodump.Roms.Add(key, temp);
+						}
+					}
 					// If the file has a SHA-1
-					if (rom.SHA1 != null && rom.SHA1 != "")
+					else if (rom.SHA1 != null && rom.SHA1 != "")
 					{
 						if (sha1.Roms.ContainsKey(key))
 						{
@@ -281,6 +315,10 @@ namespace SabreTools
 			// Now, output all of the files to the output directory
 			_logger.User("DAT information created, outputting new files");
 			bool success = true;
+			if (nodump.Roms.Count > 0)
+			{
+				success &= Output.WriteDatfile(nodump, outdir, _logger);
+			}
 			if (sha1.Roms.Count > 0)
 			{
 				success &= Output.WriteDatfile(sha1, outdir, _logger);

OfflineMerge/OfflineMerge.cs

@@ -144,10 +144,7 @@ namespace SabreTools
 			{
 				// First get the combination Dictionary of currentAllMerged and currentNewMerged
 				_logger.User("Adding Current and New Merged DATs to the dictionary");
-				DatData completeDats = new DatData
-				{
-					Roms = new Dictionary<string, List<RomData>>(),
-				};
+				DatData completeDats = new DatData();
 				completeDats = RomManipulation.Parse(_currentAllMerged, 0, 0, completeDats, _logger);
 				completeDats = RomManipulation.Parse(_currentNewMerged, 0, 0, completeDats, _logger);
 
@@ -201,10 +198,7 @@ namespace SabreTools
 
 				// Now create the New Missing dictionary [(Net New)+(currentMissingMerged-(Unneeded))]
 				_logger.User("Creating and populating New Missing dictionary");
-				DatData midMissing = new DatData
-				{
-					Roms = new Dictionary<string, List<RomData>>(),
-				};
+				DatData midMissing = new DatData();
 				midMissing = RomManipulation.Parse(_currentMissingMerged, 0, 0, midMissing, _logger);
 				foreach (string key in unneeded.Keys)
 				{
@@ -454,10 +448,7 @@ namespace SabreTools
 			{
 				// Now create the Have dictionary [(currentAllMerged)-(currentMissingMerged)]
 				_logger.User("Creating and populating Have dictionary");
-				DatData midHave = new DatData
-				{
-					Roms = new Dictionary<string, List<RomData>>(),
-				};
+				DatData midHave = new DatData();
 				midHave = RomManipulation.Parse(_currentMissingMerged, 0, 0, midHave, _logger);
 				midHave = RomManipulation.Parse(_currentAllMerged, 0, 0, midHave, _logger);
 				Dictionary<string, List<RomData>> have = new Dictionary<string, List<RomData>>();
@@ -527,10 +518,7 @@ namespace SabreTools
 			{
 				// Now create the Have dictionary [(currentNewMerged)-(currentMissingMerged)]
 				_logger.User("Creating and populating Have dictionary");
-				DatData midHave = new DatData
-				{
-					Roms = new Dictionary<string, List<RomData>>(),
-				};
+				DatData midHave = new DatData();
 				midHave = RomManipulation.Parse(_currentMissingMerged, 0, 0, midHave, _logger);
 				midHave = RomManipulation.Parse(_currentNewMerged, 0, 0, midHave, _logger);
 				Dictionary<string, List<RomData>> have = new Dictionary<string, List<RomData>>();

SabreHelper/RomManipulation.cs

@@ -100,6 +100,12 @@ namespace SabreTools.Helper
 		/// <returns>DatData object representing the read-in data</returns>
 		public static DatData Parse(string filename, int sysid, int srcid, DatData datdata, Logger logger, bool keep = false)
 		{
+			// Make sure there's a dictionary to read to
+			if (datdata.Roms == null)
+			{
+				datdata.Roms = new Dictionary<string, List<RomData>>();
+			}
+
 			// Prepare all internal variables
 			XmlReader subreader, headreader, flagreader;
 			bool superdat = false, nodump = false, empty = true;

UncompressedSize/UncompressedSize.cs

@@ -34,10 +34,7 @@ namespace SabreTools
 			long size = 0;
 			foreach (string filename in inputs)
 			{
-				DatData datdata = new DatData
-				{
-					Roms = new Dictionary<string, List<RomData>>(),
-				};
+				DatData datdata = new DatData();
 				datdata = RomManipulation.Parse(filename, 0, 0, datdata, logger);
 				foreach (List<RomData> romlist in datdata.Roms.Values)
 				{