From b50b1ac90c972582fa66d5e1a6ee8ddbe016e5dd Mon Sep 17 00:00:00 2001
From: mattias <mattias@idefix.freepascal.org>
Date: Fri, 13 Nov 2020 01:29:23 +0000
Subject: [PATCH] fcl-passrc: useanalyzer: fixed implementation class forward

---
 .../fcl-passrc/src/pasuseanalyzer.pas         | 11 +++-----
 .../fcl-passrc/tests/tcuseanalyzer.pas        | 25 +++++++++++++++++++
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/compiler/packages/fcl-passrc/src/pasuseanalyzer.pas b/compiler/packages/fcl-passrc/src/pasuseanalyzer.pas
index 7b31308..5faf8d4 100644
--- a/compiler/packages/fcl-passrc/src/pasuseanalyzer.pas
+++ b/compiler/packages/fcl-passrc/src/pasuseanalyzer.pas
@@ -3159,15 +3159,10 @@ begin
 end;
 
 function TPasAnalyzer.IsSpecializedGenericType(El: TPasElement): boolean;
-var
-  GenScope: TPasGenericScope;
 begin
-  if El is TPasGenericType then
-    begin
-    GenScope:=El.CustomData as TPasGenericScope;
-    if (GenScope<>nil) and (GenScope.SpecializedFromItem<>nil) then
-      exit(true);
-    end;
+  if (El is TPasGenericType) and (El.CustomData is TPasGenericScope)
+      and (TPasGenericScope(El.CustomData).SpecializedFromItem<>nil) then
+    exit(true);
   Result:=false;
 end;
 
diff --git a/compiler/packages/fcl-passrc/tests/tcuseanalyzer.pas b/compiler/packages/fcl-passrc/tests/tcuseanalyzer.pas
index 2ba2095..cbbe4a9 100644
--- a/compiler/packages/fcl-passrc/tests/tcuseanalyzer.pas
+++ b/compiler/packages/fcl-passrc/tests/tcuseanalyzer.pas
@@ -78,6 +78,7 @@ type
     procedure TestM_Class;
     procedure TestM_ClassForward;
     procedure TestM_Class_Property;
+    procedure TestM_ClassForward_Generic;
     procedure TestM_Class_PropertyProtected;
     procedure TestM_Class_PropertyOverride;
     procedure TestM_Class_PropertyOverride2;
@@ -1153,6 +1154,30 @@ begin
   AnalyzeProgram;
 end;
 
+procedure TTestUseAnalyzer.TestM_ClassForward_Generic;
+begin
+  StartUnit(false);
+  Add([
+  '{$mode delphi}',
+  'interface',
+  'type',
+  '  {tobject_used}TObject = class',
+  '  end;',
+  '  TBird = class;',
+  '  TAnt = class end;',
+  '  TBird = class end;',
+  'implementation',
+  'type',
+  '  TBird2 = class;',
+  '  TAnt2 = class end;',
+  '  TBird2 = class end;',
+  'var Bird2: TBird2;',
+  'begin',
+  '  if Bird2=nil then;',
+  '']);
+  AnalyzeUnit;
+end;
+
 procedure TTestUseAnalyzer.TestM_Class_PropertyProtected;
 begin
   StartUnit(false);