Transform 'try { try {} catch {} } finally {}' to 'try {} catch {} finally {}'. Closes #77.

ICSharpCode.Decompiler/Ast/Transforms/PatternStatementTransform.cs

@@ -40,6 +40,8 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 				TransformAutomaticProperties(compilationUnit);
 			if (context.Settings.AutomaticEvents)
 				TransformAutomaticEvents(compilationUnit);
+			
+			TransformTryCatchFinally(compilationUnit);
 		}
 		
 		/// <summary>
@@ -652,6 +654,33 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 		}
 		#endregion
 		
+		#region Try-Catch-Finally
+		static readonly TryCatchStatement tryCatchFinallyPattern = new TryCatchStatement {
+			TryBlock = new BlockStatement {
+				new TryCatchStatement {
+					TryBlock = new AnyNode(),
+					CatchClauses = { new Repeat(new AnyNode()) }
+				}
+			},
+			FinallyBlock = new AnyNode()
+		};
+		
+		/// <summary>
+		/// Simplify nested 'try { try {} catch {} } finally {}'.
+		/// This transformation must run after the using/lock tranformations.
+		/// </summary>
+		void TransformTryCatchFinally(AstNode compilationUnit)
+		{
+			foreach (var tryFinally in compilationUnit.Descendants.OfType<TryCatchStatement>()) {
+				if (tryCatchFinallyPattern.Match(tryFinally) != null) {
+					TryCatchStatement tryCatch = (TryCatchStatement)tryFinally.TryBlock.Statements.Single();
+					tryFinally.TryBlock = tryCatch.TryBlock.Detach();
+					tryCatch.CatchClauses.MoveTo(tryFinally.CatchClauses);
+				}
+			}
+		}
+		#endregion
+		
 		#region Pattern Matching Helpers
 		sealed class TypePattern : Pattern
 		{

ICSharpCode.Decompiler/Tests/ExceptionHandling.cs

@@ -22,4 +22,28 @@ public class ExceptionHandling
 			throw;
 		}
 	}
+	
+	public void TryCatchFinally()
+	{
+		try {
+			Console.WriteLine("Try");
+		} catch (Exception ex) {
+			Console.WriteLine(ex.Message);
+		} finally {
+			Console.WriteLine("Finally");
+		}
+	}
+	
+	public void TryCatchMultipleHandlers()
+	{
+		try {
+			Console.WriteLine("Try");
+		} catch (InvalidOperationException ex) {
+			Console.WriteLine(ex.Message);
+		} catch (Exception ex) {
+			Console.WriteLine(ex.Message);
+		} catch {
+			Console.WriteLine("other");
+		}
+	}
 }