[Patch] GTK2: Clipboard.AsText crashs sometimes.

Original Reporter info from Mantis: engkin @engkin

• Reporter name:

Description:

In \lcl\interfaces\gtk2\gtk2winapi.inc file, Function TGtk2WidgetSet.ClipboardGetData: SupportedFormats gets the same address from SelData.Data:

SupportedFormats:=PGdkAtom(SelData.Data);

at the end of ClipboardGetData both get freed:

      finally
        if SupportedFormats<>nil then FreeMem(SupportedFormats);
        if SelData.Data<>nil then FreeMem(SelData.Data); //<--- this may cause a crash
      end;
    end;

The attached patch

Steps to reproduce:

Download the project which I'll attach in a comment.
Compile and run after using GTK2 as the widgetset.
Copy any image from the forum and click the button labeled "Clipboard.AsText".

Additional information:

Forum member dbannon (Davo) reported the issue here:
http://forum.lazarus.freepascal.org/index.php/topic,43750.0.html

He also provided a sample project which I'll include in this report in the first comment.

Mantis conversion info:

• Mantis ID: 34795
• OS: Linux/Win
• OS Build: any
• Version: 1.8.2
• Fixed in revision: r60064 (#6831ce0d)