Fix bug in AwaitInFinallyTransform

ICSharpCode.Decompiler.Tests/TestCases/Correctness/Async.cs

@@ -43,6 +43,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
 			await AwaitCatch(Task.FromResult(1));
 			await AwaitMultipleCatchBlocks(Task.FromResult(1));
 			await AwaitMultipleCatchBlocks2(Task.FromResult(1));
+			Console.WriteLine(await AwaitInComplexFinally());
 			try {
 				await AwaitFinally(Task.FromResult(2));
 			} catch (Exception ex) {
@@ -219,6 +220,33 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
 			Console.WriteLine("End Method");
 		}
 
+		public static async Task<int> AwaitInComplexFinally()
+		{
+			Console.WriteLine("a");
+			try {
+				Console.WriteLine("b");
+				await Task.Delay(1);
+				Console.WriteLine("c");
+			} catch (Exception ex) {
+				await Task.Delay(ex.HResult);
+			} finally {
+				Console.WriteLine("d");
+				int i = 0;
+				if (Console.CapsLock) {
+					i++;
+					await Task.Delay(i);
+				} else {
+					while (i < 5) {
+						Console.WriteLine("i: " + i);
+						i++;
+					}
+				}
+				Console.WriteLine("e");
+			}
+			Console.WriteLine("f");
+			return 1;
+		}
+
 		public async Task AwaitInCatchAndFinally(Task<int> task1, Task<int> task2, Task<int> task3)
 		{
 			try {

ICSharpCode.Decompiler/IL/ControlFlow/AwaitInCatchTransform.cs

@@ -231,24 +231,37 @@ namespace ICSharpCode.Decompiler.IL.ControlFlow
 					continue;
 				if (globalCopyVarSplitted.StoreCount != 1 || globalCopyVarSplitted.LoadCount != 0)
 					continue;
-				context.Step("Inline finally block with await", tryCatch.Handlers[0]);
 				var cfg = new ControlFlowGraph(container, context.CancellationToken);
 				var exitOfFinallyNode = cfg.GetNode(exitOfFinally);
 				var entryPointOfFinallyNode = cfg.GetNode(entryPointOfFinally);
-				var nodes = new Stack<ControlFlowNode>(new[] { entryPointOfFinallyNode });
-				var blocksInFinally = new HashSet<Block>();
+
+				var additionalBlocksInFinally = new HashSet<Block>();
 				var invalidExits = new List<ControlFlowNode>();
-				while (nodes.Count > 0) {
-					var currentNode = nodes.Pop();
-					if (currentNode != exitOfFinallyNode) {
-						foreach (var successor in currentNode.Successors)
-							nodes.Push(successor);
-						if (entryPointOfFinallyNode.Dominates(currentNode))
-							blocksInFinally.Add((Block)currentNode.UserData);
+
+				TraverseDominatorTree(entryPointOfFinallyNode);
+
+				void TraverseDominatorTree(ControlFlowNode node)
+				{
+					if (entryPointOfFinallyNode != node) {
+						if (entryPointOfFinallyNode.Dominates(node))
+							additionalBlocksInFinally.Add((Block)node.UserData);
 						else
-							invalidExits.Add(currentNode);
+							invalidExits.Add(node);
+					}
+
+					if (node == exitOfFinallyNode)
+						return;
+
+					foreach (var child in node.DominatorTreeChildren) {
+						TraverseDominatorTree(child);
 					}
 				}
+
+				if (invalidExits.Any())
+					continue;
+
+				context.Step("Inline finally block with await", tryCatch.Handlers[0]);
+
 				foreach (var blockToRemove in blocksToRemove) {
 					blockToRemove.Remove();
 				}
@@ -264,7 +277,7 @@ namespace ICSharpCode.Decompiler.IL.ControlFlow
 					if (branchToFinally.TargetBlock == entryPointOfFinally)
 						branchToFinally.ReplaceWith(new Branch(afterFinally));
 				}
-				foreach (var newBlock in blocksInFinally) {
+				foreach (var newBlock in additionalBlocksInFinally) {
 					newBlock.Remove();
 					finallyContainer.Blocks.Add(newBlock);
 				}