Fix for issue #1243: Header DblClickResize and HeaderClickAutoSort: S…

…tore if previous message was a double click,

Source/VirtualTrees.Header.pas

@@ -333,6 +333,7 @@   TVTHeader = class(TPersistent)
     FDragImage                   : TVTDragImage;            //drag image management during header drag
     FLastWidth                   : TDimension;              //Used to adjust spring columns. This is the width of all visible columns, not the header rectangle.
     FRestoreSelectionColumnIndex : Integer;                 //The column that is used to implement the coRestoreSelection option
+    FWasDoubleClick              : Boolean;                 // The previous mouse message was for a double click, that allows us to process mouse-up-messages differently
     function GetMainColumn : TColumnIndex;
     function GetUseColumns : Boolean;
     function IsFontStored : Boolean;
@@ -1520,9 +1521,11 @@ function TVTHeader.HandleMessage(var Message : TMessage) : Boolean;
             CheckBoxHit := False;
           end;
         end;
+        fWasDoubleClick := False;
       end;
     WM_LBUTTONDBLCLK, WM_NCLBUTTONDBLCLK, WM_NCMBUTTONDBLCLK, WM_NCRBUTTONDBLCLK :
       begin
+        fWasDoubleClick := True;
         if Message.Msg <> WM_LBUTTONDBLCLK then
           with TWMNCLButtonDblClk(Message) do
             P := FOwner.ScreenToClient(Point(XCursor, YCursor))
@@ -1664,6 +1667,7 @@ function TVTHeader.HandleMessage(var Message : TMessage) : Boolean;
             HandleMessage := TVirtualTreeColumnsCracker(FColumns).HandleClick(P, TMouseButton.mbRight, True, False);
             TBaseVirtualTreeCracker(FOwner).DoHeaderMouseUp(TMouseButton.mbRight, GetShiftState, P.X, P.Y + FHeight);
           end;
+          fWasDoubleClick := False;
         end;
     //When the tree window has an active mouse capture then we only get "client-area" messages.
     WM_LBUTTONUP, WM_NCLBUTTONUP :
@@ -1729,6 +1733,7 @@ function TVTHeader.HandleMessage(var Message : TMessage) : Boolean;
           end;
           Result := True;
           Message.Result := 0;
+          fWasDoubleClick := False;
         end;
 
         case Message.Msg of
@@ -1742,14 +1747,17 @@ function TVTHeader.HandleMessage(var Message : TMessage) : Boolean;
               end;
               if FStates <> [] then
                 TBaseVirtualTreeCracker(FOwner).DoHeaderMouseUp(TMouseButton.mbLeft, KeysToShiftState(Keys), XPos, YPos);
+              fWasDoubleClick := False;
             end;
           WM_NCLBUTTONUP :
             begin
               with TWMNCLButtonUp(Message) do
                 P := FOwner.ScreenToClient(Point(XCursor, YCursor));
-              TVirtualTreeColumnsCracker(FColumns).HandleClick(P, TMouseButton.mbLeft, True, False);
+              if not fWasDoubleClick then
+                TVirtualTreeColumnsCracker(FColumns).HandleClick(P, TMouseButton.mbLeft, True, False);
               TBaseVirtualTreeCracker(FOwner).DoHeaderMouseUp(TMouseButton.mbLeft, GetShiftState, P.X, P.Y + FHeight);
               Result := True;
+              fWasDoubleClick := False;
             end;
         end;