From 052d0e38a948680ece6c99885eba9c7dbf176bd9 Mon Sep 17 00:00:00 2001
From: Ivan Bondarev <ibond84@googlemail.com>
Date: Fri, 7 Apr 2023 14:09:53 +0200
Subject: [PATCH] #2833

---
 TestSuite/Deconstructs2.pas                      | 16 ++++++++++++++++
 .../SyntaxTreeVisitorNodes/Patterns.cs           |  2 ++
 2 files changed, 18 insertions(+)
 create mode 100644 TestSuite/Deconstructs2.pas

diff --git a/TestSuite/Deconstructs2.pas b/TestSuite/Deconstructs2.pas
new file mode 100644
index 000000000..d47b21bf0
--- /dev/null
+++ b/TestSuite/Deconstructs2.pas
@@ -0,0 +1,16 @@
+var i: integer;
+type
+  t1 = class
+    procedure Deconstruct;
+    begin
+      i := 1;
+    end;
+  end;
+  
+begin
+  if new t1 is t1(var a) then
+    begin
+      i := 2;
+    end;
+  assert(i = 2);
+end.
\ No newline at end of file
diff --git a/TreeConverter/TreeConversion/SyntaxTreeVisitorNodes/Patterns.cs b/TreeConverter/TreeConversion/SyntaxTreeVisitorNodes/Patterns.cs
index 99dc7da6f..18cdb615d 100644
--- a/TreeConverter/TreeConversion/SyntaxTreeVisitorNodes/Patterns.cs
+++ b/TreeConverter/TreeConversion/SyntaxTreeVisitorNodes/Patterns.cs
@@ -93,6 +93,8 @@ namespace PascalABCCompiler.TreeConverter
             out type_node[] parameterTypes)
         {
             parameterTypes = new type_node[givenParameterTypes.Length];
+            if (candidate.parameters.Count == 0)
+                return false;
             candidate.parameters[0].name = "Self"; // SSM 23.06.20 #2268 - это если в NET где-то такое нашли
             var selfParameter = candidate.is_extension_method ? candidate.parameters.FirstOrDefault(IsSelfParameter) : null;
             Debug.Assert(!candidate.is_extension_method || selfParameter != null, "Couldn't find self parameter in extension method");