[Full-disclosure] Does this unofficial WMF patch cause printing problems?
steve at unixwiz.net
Tue Jan 3 23:32:29 GMT 2006
On Wed, Jan 04, 2006 at 12:59:04AM +0200, Valdis Shkesters wrote:
> Today I received information from one corporative user
> that installation of unofficial WMF patch (wmffix_hexblog13.exe)
> on Windows XP workstation causes to him network printing problems.
> The problem was solved via System Restore.
It would not surprise me.
GDI is used not only by the graphics on the screen, but also by the
printing subsystem. Escape() is commonly used by applications to pass
raw data (particularly *Postscript* data) through the driver, out
the port monitor, and off to a device.
Setting an abort procedure is something an application can do to
plant a callback for GDI to use to let the application regain
control during rendering (I think it's every 200 msec or so). Most
of the time the application returns "Keep going", but it can return
a "please cancel", perhaps in response to a user clicking same.
I could imagine an application actually *relying* on those callbacks
for some purpose, though I doubt it's good practice. In any case, I
can't speculate on the effects but can certainly imagine that it's
related to printer "stuff".
Steve (who writes printing system components)
Stephen J Friedl | Security Consultant | UNIX Wizard | +1 714 544-6561
www.unixwiz.net | Tustin, Calif. USA | Microsoft MVP | steve at unixwiz.net
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