From e597ae13069861d92fb752df14caf4faceab601a Mon Sep 17 00:00:00 2001
From: juha <juha@lazarus-ide.org>
Date: Thu, 17 Nov 2011 20:16:25 +0000
Subject: [PATCH] IDE: added a sanity check about if ListView.Selected is
 assigned. Issue #19819

git-svn-id: trunk@33595 -
---
 ide/newdialog.pas | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/ide/newdialog.pas b/ide/newdialog.pas
index d65bc17244..18c323a531 100644
--- a/ide/newdialog.pas
+++ b/ide/newdialog.pas
@@ -203,26 +203,27 @@ begin
     NewFile:=TNewItemProjectFile(FNewItem);
     if (NewFile.Descriptor is TFileDescInheritedItem) then
     begin
-      AInheritedNode := nil;
       // If we are inheriting from a form
       if (NewFile.Descriptor is TFileDescInheritedComponent) then begin
         InhCompItem:=TFileDescInheritedComponent(NewFile.Descriptor);
         AInheritedNode := InheritableComponentsListView.Selected;
-        // load the ancestor component
-        AnUnitInfo:=TUnitInfo(AInheritedNode.Data);
-        if LazarusIDE.DoOpenComponent(AnUnitInfo.Filename,
-          [ofOnlyIfExists,ofQuiet,ofLoadHiddenResource,ofUseCache],[],
-          AncestorComponent)<>mrOk then
-        begin
-          MessageDlg(lisErrorOpeningComponent,
-            lisUnableToOpenAncestorComponent, mtError, [mbCancel], 0);
-          exit;
+        if Assigned(AInheritedNode) then begin
+          // load the ancestor component
+          AnUnitInfo:=TUnitInfo(AInheritedNode.Data);
+          if LazarusIDE.DoOpenComponent(AnUnitInfo.Filename,
+            [ofOnlyIfExists,ofQuiet,ofLoadHiddenResource,ofUseCache],[],
+            AncestorComponent)<>mrOk then
+          begin
+            MessageDlg(lisErrorOpeningComponent,
+              lisUnableToOpenAncestorComponent, mtError, [mbCancel], 0);
+            exit;
+          end;
+          // Set the resource class of the file descriptor
+          InhCompItem.ResourceClass := TPersistentClass(AncestorComponent.ClassType);
+          InhCompItem.InheritedUnit := AnUnitInfo;
+          InhCompItem.DeclareClassVariable := not AncestorComponent.ClassType.InheritsFrom(TFrame);
+          //DebugLn(['TNewOtherDialog.OKButtonClick ',InhCompItem.InheritedUnit.Filename,' ',dbgsname(InhCompItem.ResourceClass)]);
         end;
-        // Set the resource class of the file descriptor
-        InhCompItem.ResourceClass := TPersistentClass(AncestorComponent.ClassType);
-        InhCompItem.InheritedUnit := AnUnitInfo;
-        InhCompItem.DeclareClassVariable := not AncestorComponent.ClassType.InheritsFrom(TFrame);
-        //DebugLn(['TNewOtherDialog.OKButtonClick ',InhCompItem.InheritedUnit.Filename,' ',dbgsname(InhCompItem.ResourceClass)]);
       end
       else
       begin