[qt5] unexpected result after FillRect when pen style is psPattern

[Valdas]

Code to try (FormPaint event):

Code: Pascal  [Select][+][-]

1. procedure TForm1.FormPaint(Sender: TObject);
2. const
3.   RASTAS__TASKELIAI_1_1: TPenPattern = (5, 5);
4. begin
5.     color := clWhite;
6.     with Canvas do begin
7.         Pen.Cosmetic := TRUE;
8.         Pen.Width := 1;
9.  
10.         Pen.Color := clRed;
11.  
12.         Brush.Color := clSkyBlue;
13.  
14.         FillRect(0, 0, 50, 50); // <----- this
15.  
16.         Brush.Style := bsClear; // no effect
17.         Brush.Color := clNone; // no effect
18.  
19.         Pen.Style := psPattern;
20.         Pen.SetPattern(RASTAS__TASKELIAI_1_1);
21.  
22.         Line(0, 100, 100, 100);
23.     end;
24. end;
25.  

When FillRect is commented out (first attachment) I get only red dashed line as expected.
When FillRect is active then I get dashed line with brush.color dashes in between the red dashes.

In Gtk2 widgetset I always get red dashed line as expected.

Is this a bug or does this only happen on my system?

---------
Lazarus 2.3.0 (rev main-2_3-2889-g1b9d3d4cbf) FPC 3.2.2 x86_64-linux-gtk2
qt5 v5.15.8
yay qt5pas: 1 community/qt5pas 2.6.2.2.4-1 (479.3 KiB 2.3 MiB) (Installed: 2.6.main-1)

[zeljko]

I can confirm your observation on Qt, Qt5 and Qt6 under X11. Please open bug report and attach example project.

[zeljko]

Workaround:
...
      SaveHandleState; {<-------  add this}
      Brush.Color := clSkyBlue;

      FillRect(0, 0, 50, 50); // <----- this
      RestoreHandleState; {<------- add this}

[Valdas]

Reported: https://gitlab.com/freepascal.org/lazarus/lazarus/-/issues/40165.

[zeljko]

Thanks, better workaround is to call
LCLIntf.SetBkColor(Handle, clNone);
instead of Brush.Color := clNone, or if you call
Brush.Style := bsClear or Brush.Color := clNone call
Canvas.GetUpdatedHandle([csBrushValid]); after.