From e549db0714863f02fb4d71fceb2cddfdf4207c6f Mon Sep 17 00:00:00 2001
From: Bob Sun <bob@mssun.me>
Date: Sat, 3 Jun 2017 17:50:33 -0700
Subject: [PATCH] Change notification observer from "showPassword" to
 "decryptThenShowPassword"   - avoid crash when password has been deleted

---
 .../PasswordDetailTableViewController.swift   | 22 +++++++++++--------
 pass/Helpers/Utils.swift                      |  6 ++---
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/pass/Controllers/PasswordDetailTableViewController.swift b/pass/Controllers/PasswordDetailTableViewController.swift
index 79e2742..97c5fbd 100644
--- a/pass/Controllers/PasswordDetailTableViewController.swift
+++ b/pass/Controllers/PasswordDetailTableViewController.swift
@@ -101,10 +101,10 @@ class PasswordDetailTableViewController: UITableViewController, UIGestureRecogni
         NotificationCenter.default.addObserver(self, selector: #selector(setShouldPopCurrentView), name: .passwordStoreChangeDiscarded, object: nil)
         
         // reset the data table if some password (maybe another one) has been updated
-        NotificationCenter.default.addObserver(self, selector: #selector(showPassword), name: .passwordStoreUpdated, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(decryptThenShowPassword), name: .passwordStoreUpdated, object: nil)
         
         // reset the data table if the disaply settings have been changed
-        NotificationCenter.default.addObserver(self, selector: #selector(showPassword), name: .passwordDetailDisplaySettingChanged, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(decryptThenShowPassword), name: .passwordDetailDisplaySettingChanged, object: nil)
     }
     
     override func viewDidAppear(_ animated: Bool) {
@@ -140,20 +140,24 @@ class PasswordDetailTableViewController: UITableViewController, UIGestureRecogni
         return passphrase
     }
     
-    private func decryptThenShowPassword() {
+    @objc private func decryptThenShowPassword() {
+        guard let passwordEntity = passwordEntity else {
+            Utils.alert(title: "Cannot Show Password", message: "The password does not exist.", controller: self, handler: {(UIAlertAction) -> Void in
+                self.navigationController!.popViewController(animated: true)
+            })
+            return
+        }
         DispatchQueue.global(qos: .userInitiated).async {
             // decrypt password
             do {
-                self.password = try self.passwordStore.decrypt(passwordEntity: self.passwordEntity!, requestPGPKeyPassphrase: self.requestPGPKeyPassphrase)
+                self.password = try self.passwordStore.decrypt(passwordEntity: passwordEntity, requestPGPKeyPassphrase: self.requestPGPKeyPassphrase)
             } catch {
                 DispatchQueue.main.async {
                     // remove the wrong passphrase so that users could enter it next time
                     self.passwordStore.pgpKeyPassphrase = nil
-                    let alert = UIAlertController(title: "Cannot Show Password", message: error.localizedDescription, preferredStyle: UIAlertControllerStyle.alert)
-                    alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: {(UIAlertAction) -> Void in
+                    Utils.alert(title: "Cannot Show Password", message: error.localizedDescription, controller: self, handler: {(UIAlertAction) -> Void in
                         self.navigationController!.popViewController(animated: true)
-                    }))
-                    self.present(alert, animated: true, completion: nil)
+                    })
                 }
                 return
             }
@@ -162,7 +166,7 @@ class PasswordDetailTableViewController: UITableViewController, UIGestureRecogni
         }
     }
     
-    @objc private func showPassword() {
+    private func showPassword() {
         DispatchQueue.main.async { [weak self] in
             self?.indicator.stopAnimating()
             self?.setTableData()
diff --git a/pass/Helpers/Utils.swift b/pass/Helpers/Utils.swift
index dee5411..da3b779 100644
--- a/pass/Helpers/Utils.swift
+++ b/pass/Helpers/Utils.swift
@@ -64,13 +64,13 @@ class Utils {
         return randomString
     }
     
-    static func alert(title: String, message: String, controller: UIViewController, completion: (() -> Void)?) {
+    static func alert(title: String, message: String, controller: UIViewController, handler: ((UIAlertAction) -> Void)? = nil, completion: (() -> Void)? = nil) {
         SVProgressHUD.dismiss()
         let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
-        alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
+        alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: handler))
         controller.present(alert, animated: true, completion: completion)
-
     }
+
     
     static func removePGPKeys() {
         removeFileIfExists(atPath: Globals.pgpPublicKeyPath)