From 456c05855ef1c5815e2b0a3cd7a281d87181ce5a Mon Sep 17 00:00:00 2001
From: Ivan Bondarev <ibond84@googlemail.com>
Date: Sun, 14 Feb 2021 11:10:22 +0100
Subject: [PATCH] #2445

---
 NETGenerator/NETGenerator.cs | 18 +++++++++++++++++-
 TestSuite/nil3.pas           | 14 ++++++++++++++
 TestSuite/nil4.pas           | 14 ++++++++++++++
 TestSuite/nil5.pas           | 14 ++++++++++++++
 TestSuite/nil6.pas           | 14 ++++++++++++++
 5 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 TestSuite/nil3.pas
 create mode 100644 TestSuite/nil4.pas
 create mode 100644 TestSuite/nil5.pas
 create mode 100644 TestSuite/nil6.pas

diff --git a/NETGenerator/NETGenerator.cs b/NETGenerator/NETGenerator.cs
index 348d9763c..2bd0c4224 100644
--- a/NETGenerator/NETGenerator.cs
+++ b/NETGenerator/NETGenerator.cs
@@ -8932,7 +8932,7 @@ namespace PascalABCCompiler.NETGenerator
                             il.Emit(OpCodes.Ldc_I4_0);
                             il.Emit(OpCodes.Ceq);
                         }
-                            
+
                         return;
                     }
                     else if (real_parameters[1].type.is_nullable_type && real_parameters[0] is INullConstantNode)
@@ -8984,6 +8984,22 @@ namespace PascalABCCompiler.NETGenerator
                         }
                         return;
                     }
+                    else if (real_parameters[0].type.is_generic_parameter && real_parameters[1] is INullConstantNode)
+                    { 
+                        real_parameters[0].visit(this);
+                        il.Emit(OpCodes.Box, helper.GetTypeReference(real_parameters[0].type).tp);
+                        il.Emit(OpCodes.Ldnull);
+                        EmitOperator(value);
+                        return;
+                    }
+                    else if (real_parameters[1].type.is_generic_parameter && real_parameters[0] is INullConstantNode)
+                    {
+                        il.Emit(OpCodes.Ldnull);
+                        real_parameters[1].visit(this);
+                        il.Emit(OpCodes.Box, helper.GetTypeReference(real_parameters[1].type).tp);
+                        EmitOperator(value);
+                        return;
+                    }
                 }
                 real_parameters[0].visit(this);
                 if (real_parameters.Length > 1)
diff --git a/TestSuite/nil3.pas b/TestSuite/nil3.pas
new file mode 100644
index 000000000..c77f52fe1
--- /dev/null
+++ b/TestSuite/nil3.pas
@@ -0,0 +1,14 @@
+var i: integer;
+procedure p1<T>;
+begin
+  var o: T;
+  if o = nil then
+    i := 1;
+  if o <> nil then
+    i := 2;
+end;
+
+begin
+  p1&<byte?>;
+  assert(i = 1);
+end.
\ No newline at end of file
diff --git a/TestSuite/nil4.pas b/TestSuite/nil4.pas
new file mode 100644
index 000000000..c262739ea
--- /dev/null
+++ b/TestSuite/nil4.pas
@@ -0,0 +1,14 @@
+var i: integer;
+procedure p1<T>;
+begin
+  var o: T;
+  if o = nil then
+    i := 1;
+  if o <> nil then
+    i := 2;
+end;
+
+begin
+  p1&<byte>;
+  assert(i = 2);
+end.
\ No newline at end of file
diff --git a/TestSuite/nil5.pas b/TestSuite/nil5.pas
new file mode 100644
index 000000000..624db8f95
--- /dev/null
+++ b/TestSuite/nil5.pas
@@ -0,0 +1,14 @@
+var i: integer;
+procedure p1<T>; where T:class;
+begin
+  var o: T;
+  if o = nil then
+    i := 1;
+  if o <> nil then
+    i := 2;
+end;
+
+begin
+  p1&<object>;
+  assert(i = 1);
+end.
\ No newline at end of file
diff --git a/TestSuite/nil6.pas b/TestSuite/nil6.pas
new file mode 100644
index 000000000..e560124b4
--- /dev/null
+++ b/TestSuite/nil6.pas
@@ -0,0 +1,14 @@
+var i: integer;
+procedure p1<T>;
+begin
+  var o: T;
+  if nil = o then
+    i := 1;
+  if nil <> o then
+    i := 2;
+end;
+
+begin
+  p1&<integer?>;
+  assert(i = 1);
+end.
\ No newline at end of file