【合并】未解锁高级功能状态，合并文档总大小超过20M需要弹出比较表 -- 修复

PDF Office/PDF Master/Class/PDFTools/Merge/MergeNew/KMMergeWindowController.swift

@@ -150,7 +150,12 @@ extension KMMergeWindowController {
     }
     
     func mergeFiles(files: [KMFileAttribute], size: CGSize = CGSizeZero) {
-        if !IAPProductsManager.default().isAvailableAllFunction() && files.count > 2 {
+        var size = 0.0
+        for file in files {
+            size = size + file.fileSize
+        }
+        
+        if !IAPProductsManager.default().isAvailableAllFunction() && (files.count > 2 || size > 20 * 1024 * 1024) {
             KMPurchaseCompareWindowController.sharedInstance().showWindow(nil)
             return
         }