#1942: WholeProjectDecompiler: Do not use filenames that collide with names of special devices. Note: this changes the PDB structure from multi-level folders per namespace to "dotted name" folders.

ICSharpCode.Decompiler/CSharp/WholeProjectDecompiler.cs

@@ -512,7 +512,41 @@ namespace ICSharpCode.Decompiler.CSharp
 			}
 			if (b.Length == 0)
 				b.Append('-');
-			return b.ToString();
+			string name = b.ToString();
+			if (IsReservedFileSystemName(name))
+				return name + "_";
+			return name;
+		}
+
+		static bool IsReservedFileSystemName(string name)
+		{
+			switch (name.ToUpperInvariant()) {
+				case "AUX":
+				case "COM1":
+				case "COM2":
+				case "COM3":
+				case "COM4":
+				case "COM5":
+				case "COM6":
+				case "COM7":
+				case "COM8":
+				case "COM9":
+				case "CON":
+				case "LPT1":
+				case "LPT2":
+				case "LPT3":
+				case "LPT4":
+				case "LPT5":
+				case "LPT6":
+				case "LPT7":
+				case "LPT8":
+				case "LPT9":
+				case "NUL":
+				case "PRN":
+					return true;
+				default:
+					return false;
+			}
 		}
 
 		public static string GetPlatformName(Metadata.PEFile module)

ICSharpCode.Decompiler/DebugInfo/PortablePdbWriter.cs

@@ -84,7 +84,8 @@ namespace ICSharpCode.Decompiler.DebugInfo
 
 				lock (metadata) {
 					var sourceBlob = WriteSourceToBlob(metadata, sourceText, out var sourceCheckSum);
-					var name = metadata.GetOrAddDocumentName(type.GetFullTypeName(reader).ReflectionName.Replace('.', Path.DirectorySeparatorChar) + ".cs");
+					var typeName = type.GetFullTypeName(reader).TopLevelTypeName;
+					var name = metadata.GetOrAddDocumentName(Path.Combine(WholeProjectDecompiler.CleanUpFileName(typeName.Namespace), WholeProjectDecompiler.CleanUpFileName(typeName.Name) + ".cs"));
 
 					// Create Document(Handle)
 					var document = metadata.AddDocument(name,