Fix #3392: uses of init-setters must use object-initializer syntax.

Author: siegfriedpammer

ICSharpCode.Decompiler.Tests/TestCases/Pretty/InitializerTests.cs

@@ -235,6 +235,19 @@ public interface IData
 		{
 			int Property { get; set; }
 		}
+
+#if CS90
+		public class Issue3392Type
+		{
+			public bool Flag { get; init; }
+			public List<int> List { get; } = new List<int>();
+
+			public Issue3392Type(object x)
+			{
+
+			}
+		}
+#endif
 		#endregion
 
 		private S s1;
@@ -1010,6 +1023,17 @@ public OtherItem2 Issue1345b()
 			otherItem.Data2.Nullable = 3m;
 			return otherItem;
 		}
+
+#if CS90
+		public Issue3392Type Issue3392(Issue3392Type x)
+		{
+			x = new Issue3392Type(null) {
+				Flag = false
+			};
+			x.List.AddRange(Enumerable.Range(0, 10));
+			return x;
+		}
+#endif
 #if CS60
 		public OtherItem2 Issue1345c()
 		{

ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs

@@ -103,6 +103,7 @@ void IStatementTransform.Run(Block block, int pos, StatementTransformContext con
 					return;
 			}
 			int initializerItemsCount = 0;
+			bool initializerContainsInitOnlyItems = false;
 			possibleIndexVariables.Clear();
 			currentPath.Clear();
 			isCollection = false;
@@ -113,13 +114,13 @@ void IStatementTransform.Run(Block block, int pos, StatementTransformContext con
 			// if the method is a setter we're dealing with an object initializer
 			// if the method is named Add and has at least 2 arguments we're dealing with a collection/dictionary initializer
 			while (pos + initializerItemsCount + 1 < block.Instructions.Count
-				&& IsPartOfInitializer(block.Instructions, pos + initializerItemsCount + 1, v, instType, ref blockKind, context))
+				&& IsPartOfInitializer(block.Instructions, pos + initializerItemsCount + 1, v, instType, ref blockKind, ref initializerContainsInitOnlyItems, context))
 			{
 				initializerItemsCount++;
 			}
 			// Do not convert the statements into an initializer if there's an incompatible usage of the initializer variable
 			// directly after the possible initializer.
-			if (IsMethodCallOnVariable(block.Instructions[pos + initializerItemsCount + 1], v))
+			if (!initializerContainsInitOnlyItems && IsMethodCallOnVariable(block.Instructions[pos + initializerItemsCount + 1], v))
 				return;
 			// Calculate the correct number of statements inside the initializer:
 			// All index variables that were used in the initializer have Index set to -1.
@@ -200,7 +201,7 @@ bool IsMethodCallOnVariable(ILInstruction inst, ILVariable variable)
 		bool isCollection;
 		readonly Stack<HashSet<AccessPathElement>> pathStack = new Stack<HashSet<AccessPathElement>>();
 
-		bool IsPartOfInitializer(InstructionCollection<ILInstruction> instructions, int pos, ILVariable target, IType rootType, ref BlockKind blockKind, StatementTransformContext context)
+		bool IsPartOfInitializer(InstructionCollection<ILInstruction> instructions, int pos, ILVariable target, IType rootType, ref BlockKind blockKind, ref bool initializerContainsInitOnlyItems, StatementTransformContext context)
 		{
 			// Include any stores to local variables that are single-assigned and do not reference the initializer-variable
 			// in the list of possible index variables.
@@ -255,6 +256,7 @@ bool IsPartOfInitializer(InstructionCollection<ILInstruction> instructions, int
 						return false;
 					if (blockKind != BlockKind.ObjectInitializer && blockKind != BlockKind.WithInitializer)
 						blockKind = BlockKind.ObjectInitializer;
+					initializerContainsInitOnlyItems |= lastElement.Member is IProperty { Setter.IsInitOnly: true };
 					return true;
 				default:
 					return false;