Issue in stretchblt in recent update 2.2.0 (Ubuntu 20.04.4 LTS)
lazarus / 39-Graphics

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4nlegion · 2022-03-12 02:38

Example excerpt shows use of stretchblt copying from small area to
larger on main form.
Example compiles and runs on two different machines with no errors
using 2.0.12 and FPC 3.2.0.
Example compiles and runs on 2.2.0 / 3.2.0 but without performing
stretchblt.
Any hints?

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
Magnify();var    x,y: integer;    b: boolean;begin        x :=
mouse.CursorPos.x-form1.Left-5;        y :=
mouse.CursorPos.y-form1.top-36;        x := 15 + iif(Random>0.5,1,0); 
      y := 25 + iif(Random>0.5,1,0);        b := stretchblt(Form1.canv
as.Handle,240,150,320,320,Form1.canvas.Handle,iif(x>=0,x,0),iif(y>=0,y
,0),20,20,cmSrcCopy);end;

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trev · 2022-03-12 02:51

Widget set?

Have you checked the release notes for Lazarus 2.2.0?

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4nlegion · 2022-03-12 20:43

I have checked the release notes:
https://wiki.lazarus.freepascal.org/Lazarus_2.2.0_release_notes
...no mention of stretchblt or a graphics primitive that might have a
bearing. Still something changed. Perhaps an environment issue, or a
default optimization..

The widget set is the default setting in Project Options / Compiler
Options / Config and Target : Current LCLWidgetSet: "gtk2"

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trev · 2022-03-12 23:03

Clone the git repo, compile Lazarus main, if the issue still occurs,
then use git-bisect to find the commit that introduced the bug.