diff --git a/components/codetools/linkscanner.pas b/components/codetools/linkscanner.pas
index ca04b3eec3..5fb98f0ab3 100644
--- a/components/codetools/linkscanner.pas
+++ b/components/codetools/linkscanner.pas
@@ -1583,9 +1583,13 @@ function TLinkScanner.CursorToCleanPos(ACursorPos: integer; ACode: pointer;
 // 0=valid CleanPos
 //-1=CursorPos was skipped, CleanPos is between two links
 // 1=CursorPos beyond scanned code
-var i, j: integer;
+var
+  i, j, SkippedCleanPos: integer;
+  SkippedPos: boolean;
 begin
   i:=0;
+  SkippedPos:=false;
+  SkippedCleanPos:=-1;
   while i<LinkCount do begin
 //writeln('[TLinkScanner.CursorToCleanPos] A ACursorPos=',ACursorPos,', Code=',Links[i].Code=ACode,', Links[i].SrcPos=',Links[i].SrcPos,', Links[i].CleanedPos=',Links[i].CleanedPos);
     if (Links[i].Code=ACode) and (Links[i].SrcPos<=ACursorPos) then begin
@@ -1601,8 +1605,13 @@ begin
         while (j<LinkCount) and (Links[j].Code<>ACode) do inc(j);
 //writeln('[TLinkScanner.CursorToCleanPos] D j=',j);
         if (j<LinkCount) and (Links[j].SrcPos>ACursorPos) then begin
-          Result:=-1; // CursorPos was skipped, CleanPos is between two links
-          exit;
+          if not SkippedPos then begin
+            // CursorPos was skipped, CleanPos is between two links
+            SkippedPos:=true;
+            SkippedCleanPos:=ACleanPos;
+          end;
+          // if this is an double included file,
+          // this position can be in clean code -> search next
         end;
         // search next
         i:=j-1;
@@ -1611,14 +1620,23 @@ begin
 //writeln('[TLinkScanner.CursorToCleanPos] E length(FCleanedSrc)=',length(FCleanedSrc));
         if ACleanPos<=length(FCleanedSrc) then
           Result:=0  // valid position
-        else
-          Result:=1; // cursor beyond scanned code
+        else begin
+          if SkippedPos then begin
+            Result:=-1;
+            ACleanPos:=SkippedCleanPos;
+          end else
+            Result:=1; // cursor beyond scanned code
+        end;
         exit;
       end;
     end;
     inc(i);
   end;
-  Result:=1;
+  if SkippedPos then begin
+    Result:=-1;
+    ACLeanPos:=SkippedCleanPos;
+  end else
+    Result:=1;
 end;
 
 function TLinkScanner.CleanedPosToCursor(ACleanedPos: integer;
diff --git a/components/codetools/methodjumptool.pas b/components/codetools/methodjumptool.pas
index 99fba09688..f633da9333 100644
--- a/components/codetools/methodjumptool.pas
+++ b/components/codetools/methodjumptool.pas
@@ -34,8 +34,6 @@ interface
 
 {$I codetools.inc}
 
-{ $DEFINE CTDEBUG}
-
 uses
   {$IFDEF MEM_CHECK}
   MemCheck,
@@ -248,7 +246,7 @@ writeln('TMethodJumpingCodeTool.FindJumpPoint B');
 {$ENDIF}
   // find the CursorPos in cleaned source
   r:=CaretToCleanPos(CursorPos, CleanCursorPos);
-  if (r<>0) and (r<>-1) then 
+  if (r<>0) and (r<>-1) then
     RaiseException('Cursor outside of code');
   GetLineInfo(CleanCursorPos,LineStart,LineEnd,FirstAtomStart,LastAtomEnd);
   if CleanCursorPos<FirstAtomStart then CleanCursorPos:=FirstAtomStart;
@@ -264,7 +262,6 @@ writeln('TMethodJumpingCodeTool.FindJumpPoint B');
 {$IFDEF CTDEBUG}
 writeln('TMethodJumpingCodeTool.FindJumpPoint C ',NodeDescriptionAsString(CursorNode.Desc));
 {$ENDIF}
-
   // first test if in a class
   ClassNode:=CursorNode;
   while (ClassNode<>nil) and (ClassNode.Desc<>ctnClass) do
diff --git a/ide/runparamsopts.pas b/ide/runparamsopts.pas
index b509a42ccd..879a37d1cc 100644
--- a/ide/runparamsopts.pas
+++ b/ide/runparamsopts.pas
@@ -131,7 +131,9 @@ type
     procedure SetupEnvironmentPage;
     procedure SetOptions(NewOptions: TRunParamsOptions);
     procedure FillSystemVariablesListView;
+    procedure FillUserOverridesListView;
     procedure SaveToOptions;
+    procedure SaveUserOverrides;
   public
     constructor Create(AnOwner: TComponent); override;
     property Options: TRunParamsOptions read fOptions write SetOptions;
@@ -542,7 +544,6 @@ begin
     Width:=100;
     Caption:='Add';
     OnClick:=@UserOverridesAddButtonClick;
-    Enabled:=false;
     Visible:=true;
   end;
 
@@ -555,7 +556,6 @@ begin
     Width:=100;
     Caption:='Edit';
     OnClick:=@UserOverridesEditButtonClick;
-    Enabled:=false;
     Visible:=true;
   end;
 
@@ -568,7 +568,6 @@ begin
     Width:=100;
     Caption:='Delete';
     OnClick:=@UserOverridesDeleteButtonClick;
-    Enabled:=false;
     Visible:=true;
   end;
 
@@ -635,24 +634,55 @@ begin
 end;
 
 procedure TRunParamsOptsDlg.UserOverridesAddButtonClick(Sender: TObject);
-var Variable, Value: string;
+var
+  Variable, Value: string;
+  NewLI, SelLI: TListItem;
 begin
-  Variable:='';
-  Value:='';
+  SelLI:=SystemVariablesListView.Selected;
+  if SelLI<>nil then begin
+    Variable:=SelLI.Caption;
+    Value:=SelLI.SubItems[0];
+  end else begin
+    Variable:='';
+    Value:='';
+  end;
   if ShowSysVarUserOverrideDialog(Variable,Value)=mrOk then begin
-
-    
+    NewLI:=UserOverridesListView.Items.Add;
+    NewLI.Caption:=Variable;
+    NewLI.SubItems[0]:=Value;
+    UserOverridesListView.Selected:=NewLI;
   end;
 end;
 
 procedure TRunParamsOptsDlg.UserOverridesEditButtonClick(Sender: TObject);
+var
+  Variable, Value: string;
+  SelLI: TListItem;
 begin
-
+  SelLI:=UserOverridesListView.Selected;
+  if SelLI=nil then exit;
+  Variable:=SelLI.Caption;
+  Value:=SelLI.SubItems[0];
+  if ShowSysVarUserOverrideDialog(Variable,Value)=mrOk then begin
+    SelLI.Caption:=Variable;
+    SelLI.SubItems[0]:=Value;
+  end;
 end;
 
 procedure TRunParamsOptsDlg.UserOverridesDeleteButtonClick(Sender: TObject);
+var
+  SelLI: TListItem;
+  OldIndex: integer;
 begin
-
+  SelLI:=UserOverridesListView.Selected;
+  if SelLI<>nil then begin
+    OldIndex:=SelLI.Index;
+    SelLI.Delete;
+    if OldIndex=UserOverridesListView.Items.Count then
+      dec(OldIndex);
+    if OldIndex>=0 then
+      UserOverridesListView.Selected:=UserOverridesListView.Items[OldIndex];
+  end;
 end;
 
 procedure TRunParamsOptsDlg.SaveToOptions;
@@ -667,12 +697,21 @@ begin
   fOptions.Display:=Trim(DisplayEdit.Text);
   
   // environment
-
-  // ToDo: User Overrides
+  SaveUserOverrides;
 
   fOptions.IncludeSystemVariables:=IncludeSystemVariablesCheckBox.Checked;
 end;
 
+procedure TRunParamsOptsDlg.SaveUserOverrides;
+var i: integer;
+begin
+  Options.UserOverrides.Clear;
+  for i:=0 to UserOverridesListView.Items.Count-1 do begin
+    Options.UserOverrides.Values[UserOverridesListView.Items[i].Caption]:=
+      UserOverridesListView.Items[i].SubItems[0];
+  end;
+end;
+
 procedure TRunParamsOptsDlg.SetOptions(NewOptions: TRunParamsOptions);
 begin
   fOptions:=NewOptions;
@@ -687,7 +726,7 @@ begin
   
   // environment
   FillSystemVariablesListView;
-  // ToDo: User Overrides
+  FillUserOverridesListView;
   
   IncludeSystemVariablesCheckBox.Checked:=fOptions.IncludeSystemVariables;
 end;
@@ -720,5 +759,29 @@ Begin
   end;
 end;
 
+procedure TRunParamsOptsDlg.FillUserOverridesListView;
+var
+  i: integer;
+  Variable, Value: string;
+Begin
+  with UserOverridesListView.Items do begin
+    //BeginUpdate;
+    for i:=0 to Options.UserOverrides.Count-1 do begin
+      Variable:=Options.UserOverrides.Names[i];
+      Value:=Options.UserOverrides.Values[Variable];
+      if Count<=i then begin
+        // add line to listview
+        Add;
+        Item[i].SubItems.Add('');
+      end;
+      Item[i].Caption:=Variable;
+      Item[i].SubItems[0]:=Value;
+    end;
+    while Count>Options.UserOverrides.Count do
+      Delete(Count-1);
+    //EndUpdate;
+  end;
+end;
+
 
 end.
diff --git a/ide/sysvaruseroverridedlg.pas b/ide/sysvaruseroverridedlg.pas
index e875dd27fe..c6d57efe67 100644
--- a/ide/sysvaruseroverridedlg.pas
+++ b/ide/sysvaruseroverridedlg.pas
@@ -59,7 +59,7 @@ begin
     ValueEdit.Text:=Value;
     Result:=ShowModal;
     if (Result=mrOk) then begin
-      Variable:=VariableEdit.Text;
+      Variable:=Trim(VariableEdit.Text);
       Value:=ValueEdit.Text;
     end;
     Free;
@@ -69,7 +69,15 @@ end;
 { TSysVarUserOverrideDialog }
 
 procedure TSysVarUserOverrideDialog.OkButtonClick(Sender: TObject);
+var v: string;
 begin
+  v:=Trim(VariableEdit.Text);
+  if not IsValidIdent(v) then begin
+    if MessageDlg('Invalid variable name',
+      '"'+v+'" is not a valid identifier.',
+      mtWarning,[mbCancel,mbIgnore],0)=mrCancel
+    then exit;
+  end;
   ModalResult:=mrOk;
 end;
 
@@ -84,7 +92,9 @@ begin
   if LazarusResources.Find(ClassName)=nil then begin
 
     Caption:='Override system variable';
-    SetBounds((Screen.Width-400) div 2,(Screen.Height-200) div 2,400,200);
+    Width:=400;
+    Height:=170;
+    Position:=poScreenCenter;
 
     VariableLabel:=TLabel.Create(Self);
     with VariableLabel do begin
@@ -100,7 +110,7 @@ begin
       Name:='VariableEdit';
       Parent:=Self;
       SetBounds(VariableLabel.Left,VariableLabel.Top+VariableLabel.Height+2,
-        Self.ClientWidth-2*Left,Height);
+        Self.ClientWidth-2*VariableLabel.Left,Height);
       Visible:=true;
     end;
 
@@ -119,7 +129,7 @@ begin
       Name:='ValueEdit';
       Parent:=Self;
       SetBounds(ValueLabel.Left,ValueLabel.Top+ValueLabel.Height+2,
-        Self.ClientWidth-2*Left,Height);
+        Self.ClientWidth-2*ValueLabel.Left,Height);
       Visible:=true;
     end;