setting a filename in NSPrintInfo

I'm trying to set up a print dialog, so that if the user tries to save to PDF, it gets a reasonable filename.

I currently have:

NSPrintInfo* pi = [NSPrintInfo sharedPrintInfo];
NSMutableDictionary *dict = [pi dictionary];
[dict setObject: name forKey: NSPrintSavePath];
[dict setObject: name forKey: @"NSPrintSavePath"];
NSPrintOperation *op = [pdfDoc getPrintOperationForPrintInfo:pi
                                   autoRotate:YES];
[op runOperation];

the NSPrintSave field in the dictionary IS correct, but the textbox keeps coming up with ".pdf.pdf"

any thoughts on where that's coming from?

Added info:

When I print out my NSPrintInfo object, I get:

print info {
   NSBottomMargin = 90;
   NSCopies = 1;
   NSDetailedErrorReporting = 0;
   NSFaxNumber = "";
   NSFirstPage = 1;
   NSHorizonalPagination = 2;
   NSHorizontallyCentered = 1;
   NSJobDisposition = NSPrintSpoolJob;
   NSJobSavingFileNameExtensionHidden = 0;
   NSJobSavingURL = bob -- /;
   NSLastPage = 2147开发者_如何学编程483647;
   NSLeftMargin = 72;
   NSMustCollate = 1;
   NSOrientation = 0;
   NSPagesAcross = 1;
   NSPagesDown = 1;
   NSPaperName = "na-letter";
   NSPaperSize = NSSize: {612, 792};
   NSPrintAllPages = 1;
   NSPrintProtected = 0;
   NSPrintSavePath = bob;
   NSPrintTime = 0001-12-31 19:00:00 -0500;
   NSPrinter = {
       "Device Description" =     {
            NSDeviceIsPrinter = YES;
            };
       "Language Level" = 2;
       Name = "Xerox WorkCentre PE120 Series (XRX0000aa9915f0)";
       Type = "Generic PostScript Printer";
   };
   NSPrinterName = "Xerox WorkCentre PE120 Series (XRX0000aa9915f0)";
   NSRightMargin = 72;
   NSSavePath = bob;
   NSScalingFactor = 1;
   NSTopMargin = 90;
   NSVerticalPagination = 0;
   NSVerticallyCentered = 1;
}

I woud think that this would mean that the default filename to print to would be "bob", or "bob.pdf" but it's still ".pdf.pdf"...

---

The answer, it would appear, is to completely ignore the NSPrintInfo, and look at the NSPrintOperation. evidently, NSPrintOperation has a setJobTitle method, which just does The Right Thing (tm).

Now, why none of my google searching found this (all of it lead to the stuff I tried above) I really don't know...