Bug 1636725 p2. Properly save the settings chosen by the user in the Page Setup dialog on macOS. r=bobowen

Depends on D74547

Differential Revision: https://phabricator.services.mozilla.com/D74548

widget/cocoa/nsPrintDialogX.mm

@@ -188,8 +188,10 @@ nsPrintDialogServiceX::ShowPageSetup(nsPIDOMWindowOuter* aParent, nsIPrintSettin
     nsCOMPtr<nsIPrintSettingsService> printSettingsService =
         do_GetService("@mozilla.org/gfx/printsettings-service;1");
     if (printSettingsService && Preferences::GetBool("print.save_print_settings", false)) {
-      printSettingsService->SavePrintSettingsToPrefs(aNSSettings, true,
-                                                     nsIPrintSettings::kInitSaveNativeData);
+      uint32_t flags = nsIPrintSettings::kInitSaveNativeData |
+                       nsIPrintSettings::kInitSavePaperSize |
+                       nsIPrintSettings::kInitSaveOrientation | nsIPrintSettings::kInitSaveScaling;
+      printSettingsService->SavePrintSettingsToPrefs(aNSSettings, true, flags);
     }
     return NS_OK;
   }

widget/cocoa/nsPrintSettingsX.mm

@@ -24,6 +24,13 @@ NS_IMPL_ISUPPORTS_INHERITED(nsPrintSettingsX, nsPrintSettings, nsPrintSettingsX)
 nsPrintSettingsX::nsPrintSettingsX() : mAdjustedPaperWidth{0.0}, mAdjustedPaperHeight{0.0} {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
+  // Note that the app shared `sharedPrintInfo` object is special!  The system
+  // print dialog and print settings dialog update it with the values chosen
+  // by the user.  Using that object here to initialize new nsPrintSettingsX
+  // objects could mask bugs in our code where we fail to save and/or restore
+  // print settings ourselves (e.g., bug 1636725).  On other platforms we only
+  // initialize new nsPrintSettings objects from the settings that we save to
+  // prefs.  Perhaps we should stop using sharedPrintInfo here for consistency?
   mPrintInfo = [[NSPrintInfo sharedPrintInfo] copy];
   mWidthScale = COCOA_PAPER_UNITS_PER_INCH;
   mHeightScale = COCOA_PAPER_UNITS_PER_INCH;