【APPCenter】Crash编号：95 -- 修复

PDF Office/PDF Master/Class/PDFTools/Print/KMPrintWindowController.swift

@@ -359,13 +359,13 @@ extension KMPrintWindowController {
     }
     
     static func openPrintView(document: PDFDocument?) {
-        if (document != nil &&
-            document!.allowsPrinting == true) {
+        guard let document = document else { return }
+        if (document.allowsPrinting == true) {
             let printInfo = NSPrintInfo.shared
             var printOperation: NSPrintOperation = NSPrintOperation()
             let scalingMode: PDFPrintScalingMode = .pageScaleToFit
-            if document!.responds(to: NSSelectorFromString("printOperationForPrintInfo:scalingMode:autoRotate:")) {
-                printOperation = document!.printOperation(for: printInfo, scalingMode: scalingMode, autoRotate: false)!
+            if document.responds(to: NSSelectorFromString("printOperationForPrintInfo:scalingMode:autoRotate:")) {
+                printOperation = document.printOperation(for: printInfo, scalingMode: scalingMode, autoRotate: false) ?? NSPrintOperation()
             }
             
             printOperation.printPanel.options = [.showsPreview, .showsCopies, .showsOrientation, .showsPageRange, .showsPaperSize, .showsCopies, .showsPrintSelection, .showsScaling]