Fix void and no-arguments methods

ICSharpCode.Decompiler/IL/Transforms/ProxyCallReplacer.cs

@@ -36,12 +36,25 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 						if (blockContainer.Blocks.Count != 1)
 							return;
 						var block = blockContainer.Blocks[0];
-						if (block.Instructions.Count != 1)
-							return;
-						if (!block.Instructions[0].MatchLeave(blockContainer, out ILInstruction returnValue))
-							return;
-						if (!(returnValue is Call call))
+						Call call = null;
+						if (block.Instructions.Count == 1) {
+							// leave IL_0000 (call Test(ldloc this, ldloc A_1))
+							if (!block.Instructions[0].MatchLeave(blockContainer, out ILInstruction returnValue))
+								return;
+							call = returnValue as Call;
+						} else if (block.Instructions.Count == 2) {
+							// call Test(ldloc this, ldloc A_1)
+							// leave IL_0000(nop)
+							call = block.Instructions[0] as Call;
+							if (!block.Instructions[1].MatchLeave(blockContainer, out ILInstruction returnValue))
+								return;
+							if (!returnValue.MatchNop())
+								return;
+						}
+						if (call == null) {
 							return;
+						}
+
 						// check if original arguments are only correct ldloc calls
 						for (int i = 0; i < call.Arguments.Count; i++) {
 							var originalArg = call.Arguments[i];
@@ -56,25 +69,27 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 
 						newInst.Arguments.Clear();
 
-						ILInstruction thisArg = inst.Arguments[0];
+						if (inst.Arguments.Count > 0) {
+							ILInstruction thisArg = inst.Arguments[0];
 
-						// special handling for first argument (this) - the underlying issue may be somewhere else
-						// normally
-						// leave IL_0000(await(callvirt<> n__0(ldobj xxHandler(ldloca this), ldobj System.Net.Http.HttpRequestMessage(ldloca request), ldobj System.Threading.CancellationToken(ldloca cancellationToken))))
-						// would be decompiled to
-						// return await((DelegatingHandler)this).SendAsync(request, cancellationToken);
-						// this changes it to
-						// return await base.SendAsync(request, cancellationToken);
-						if (thisArg.MatchLdObj(out ILInstruction loadedObject, out IType objectType) &&
-							loadedObject.MatchLdLoca(out ILVariable loadedVar)) {
-							thisArg = new LdLoc(loadedVar);
-						}
+							// special handling for first argument (this) - the underlying issue may be somewhere else
+							// normally
+							// leave IL_0000(await(callvirt<> n__0(ldobj xxHandler(ldloca this), ldobj System.Net.Http.HttpRequestMessage(ldloca request), ldobj System.Threading.CancellationToken(ldloca cancellationToken))))
+							// would be decompiled to
+							// return await((DelegatingHandler)this).SendAsync(request, cancellationToken);
+							// this changes it to
+							// return await base.SendAsync(request, cancellationToken);
+							if (thisArg.MatchLdObj(out ILInstruction loadedObject, out IType objectType) &&
+								loadedObject.MatchLdLoca(out ILVariable loadedVar)) {
+								thisArg = new LdLoc(loadedVar);
+							}
 
-						newInst.Arguments.Add(thisArg);
+							newInst.Arguments.Add(thisArg);
 
-						// add everything except first argument
-						for (int i = 1; i < inst.Arguments.Count; i++) {
-							newInst.Arguments.Add(inst.Arguments[i]);
+							// add everything except first argument
+							for (int i = 1; i < inst.Arguments.Count; i++) {
+								newInst.Arguments.Add(inst.Arguments[i]);
+							}
 						}
 						inst.ReplaceWith(newInst);
 					}