From efa9bdc366e1c0f8e23008e2cec387f8f59d378f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=91=D0=BE=D0=BD=D0=B4=D0=B0=D1=80=D0=B5=D0=B2=20=D0=98?=
 =?UTF-8?q?=D0=B2=D0=B0=D0=BD?= <ibond84@googlemail.com>
Date: Mon, 27 Nov 2017 21:01:49 +0100
Subject: [PATCH] bug fix #568

---
 TestSuite/extensionmethods25.pas                    |  5 +++++
 TreeConverter/SymbolTable/symbol_information.cs     |  8 ++++++++
 TreeConverter/TreeConversion/syntax_tree_visitor.cs | 13 +++++++++++++
 3 files changed, 26 insertions(+)
 create mode 100644 TestSuite/extensionmethods25.pas

diff --git a/TestSuite/extensionmethods25.pas b/TestSuite/extensionmethods25.pas
new file mode 100644
index 000000000..6a281d381
--- /dev/null
+++ b/TestSuite/extensionmethods25.pas
@@ -0,0 +1,5 @@
+begin
+  var l := Lst(1,2,3);
+  l.Reverse();
+  assert(l[0]=3);
+end.
\ No newline at end of file
diff --git a/TreeConverter/SymbolTable/symbol_information.cs b/TreeConverter/SymbolTable/symbol_information.cs
index 59754e56c..cd652a4d5 100644
--- a/TreeConverter/SymbolTable/symbol_information.cs
+++ b/TreeConverter/SymbolTable/symbol_information.cs
@@ -527,6 +527,14 @@ namespace PascalABCCompiler.TreeConverter
             return 0;
         }
 
+        public bool HasOnlyExtensionMethods()
+        {
+            for (int i = 0; i < list.Count; ++i)
+                if (!(list[i].sym_info is function_node && (list[i].sym_info as function_node).is_extension_method))
+                    return false;
+            return true;
+        }
+
         public void Insert(int index, SymbolInfo item)
         {
             if (list != null)
diff --git a/TreeConverter/TreeConversion/syntax_tree_visitor.cs b/TreeConverter/TreeConversion/syntax_tree_visitor.cs
index aa1537117..341021f92 100644
--- a/TreeConverter/TreeConversion/syntax_tree_visitor.cs
+++ b/TreeConverter/TreeConversion/syntax_tree_visitor.cs
@@ -5284,6 +5284,19 @@ namespace PascalABCCompiler.TreeConverter
                                                         throw LastError();
                                                     }
                                                 }
+                                                else if (fn != null && skip_first_parameter && sil.Count() > 1 && !sil.HasOnlyExtensionMethods())
+                                                {
+                                                    function_node tmp_fn = fn;
+                                                    exprs.remove_at(0);
+                                                    sil = tmp_sil;
+                                                    fn = convertion_data_and_alghoritms.select_function(exprs, sil, subloc, syntax_nodes_parameters);
+                                                    if (fn == null)
+                                                    {
+                                                        fn = tmp_fn;
+                                                        RemoveLastError();
+                                                        exprs.AddElementFirst(exp);
+                                                    }
+                                                }
                                             }
                                             catch (Exception ex)
                                             {