[Lazarus] Possible Postscriptcanvas/QT Bug

[David Copeland]

I have submitted a Mantis report (number 20354). When I rebuilt an app
for QT I started getting access violations after a call to
TPostscriptcanvas.GettextWidth.

TApplication.HandleException Access violation
  Stack trace:
  $000000000068FC1E line 3198 of qt/qtobjects.pas
  $00000000005A78BD line 679 of qt/qtobject.inc
  $000000000051554A line 176 of include/canvas.inc
  $00000000005184CA line 1542 of include/canvas.inc
  $00000000006B040F line 1142 of postscriptcanvas.pas
  $000000000051864A line 1609 of include/canvas.inc
  $00000000006B04EE line 1193 of postscriptcanvas.pas
  $00000000006B6761 line 2086 of postscriptcanvas.pas
  $000000000051895D line 1683 of include/canvas.inc
  $00000000005160B0 line 489 of include/canvas.inc
  $0000000000528F8E
  $000000000047A10F line 51 of main.pas
  $000000000047A291 line 68 of main.pas
  $00000000005D9CCF line 2319 of include/control.inc
  $00000000006067D6 line 62 of include/buttoncontrol.inc
  $0000000000606ED5 line 174 of include/buttons.inc
  $000000000060748D line 339 of include/buttons.inc



I was able to reproduce this in a simple test app, which I supplied with
the report. Using SVN 32519, FPC 2.4.4, Linux x86_86, Suse 11.4.

Dave Copeland.