Adding to existing contact requires contact access

Previously we'd show an empty "list" of existing contacts.

// FREEBIE

Signal/src/ViewControllers/ContactsViewHelper.h

@@ -46,6 +46,10 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic, readonly) NSArray<NSString *> *blockedPhoneNumbers;
 
+// Suitable to display when the user tries to perform an action which is not possible due to the user having
+// previously denied contact access.
+@property (nonatomic, readonly) UIAlertController *missingContactAccessAlertController;
+
 - (instancetype)init NS_UNAVAILABLE;
 
 - (instancetype)initWithDelegate:(id<ContactsViewHelperDelegate>)delegate;

Signal/src/ViewControllers/ContactsViewHelper.m

@@ -297,31 +297,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - Editing
 
-- (void)presentContactViewControllerForRecipientId:(NSString *)recipientId
-                                fromViewController:(UIViewController<ContactEditingDelegate> *)fromViewController
-                                   editImmediately:(BOOL)shouldEditImmediately
-{
-    [self presentContactViewControllerForRecipientId:recipientId
-                                  fromViewController:fromViewController
-                                     editImmediately:shouldEditImmediately
-                              addToExistingCnContact:nil];
-}
-
-- (void)presentContactViewControllerForRecipientId:(NSString *)recipientId
-                                fromViewController:(UIViewController<ContactEditingDelegate> *)fromViewController
-                                   editImmediately:(BOOL)shouldEditImmediately
-                            addToExistingCnContact:(CNContact *_Nullable)addToExistingCnContact
+- (UIAlertController *)missingContactAccessAlertController
 {
-    SignalAccount *signalAccount = [self signalAccountForRecipientId:recipientId];
-
-    if (!self.contactsManager.supportsContactEditing) {
-        DDLogError(@"%@ Contact editing not supported.", self.tag);
-        // Should not expose UI that lets the user get here.
-        OWSAssert(NO);
-        return;
-    }
-
-    if (!self.contactsManager.isSystemContactsAuthorized) {
     UIAlertController *alertController = [UIAlertController
         alertControllerWithTitle:NSLocalizedString(@"EDIT_CONTACT_WITHOUT_CONTACTS_PERMISSION_ALERT_TITLE", comment
                                                    : @"Alert title for when the user has just tried to edit a "
@@ -346,7 +323,35 @@ NS_ASSUME_NONNULL_BEGIN
                                                           [[UIApplication sharedApplication] openSystemSettings];
                                                       }]];
 
-        [fromViewController presentViewController:alertController animated:YES completion:nil];
+    return alertController;
+}
+
+- (void)presentContactViewControllerForRecipientId:(NSString *)recipientId
+                                fromViewController:(UIViewController<ContactEditingDelegate> *)fromViewController
+                                   editImmediately:(BOOL)shouldEditImmediately
+{
+    [self presentContactViewControllerForRecipientId:recipientId
+                                  fromViewController:fromViewController
+                                     editImmediately:shouldEditImmediately
+                              addToExistingCnContact:nil];
+}
+
+- (void)presentContactViewControllerForRecipientId:(NSString *)recipientId
+                                fromViewController:(UIViewController<ContactEditingDelegate> *)fromViewController
+                                   editImmediately:(BOOL)shouldEditImmediately
+                            addToExistingCnContact:(CNContact *_Nullable)addToExistingCnContact
+{
+    SignalAccount *signalAccount = [self signalAccountForRecipientId:recipientId];
+
+    if (!self.contactsManager.supportsContactEditing) {
+        DDLogError(@"%@ Contact editing not supported.", self.tag);
+        // Should not expose UI that lets the user get here.
+        OWSAssert(NO);
+        return;
+    }
+
+    if (!self.contactsManager.isSystemContactsAuthorized) {
+        [fromViewController presentViewController:self.missingContactAccessAlertController animated:YES completion:nil];
         return;
     }
 

Signal/src/ViewControllers/OWSConversationSettingsTableViewController.m

@@ -275,9 +275,7 @@ NS_ASSUME_NONNULL_BEGIN
                                  actionBlock:^{
                                      TSContactThread *contactThread = (TSContactThread *)self.thread;
                                      NSString *recipientId = contactThread.contactIdentifier;
-                                     OWSAddToContactViewController *view = [OWSAddToContactViewController new];
-                                     [view configureWithRecipientId:recipientId];
-                                     [weakSelf.navigationController pushViewController:view animated:YES];
+                                     [weakSelf presentAddToContactViewControllerWithRecipientId:recipientId];
                                  }]];
     }
 
@@ -763,6 +761,26 @@ NS_ASSUME_NONNULL_BEGIN
                                                         editImmediately:YES];
 }
 
+- (void)presentAddToContactViewControllerWithRecipientId:(NSString *)recipientId
+{
+    if (!self.contactsManager.supportsContactEditing) {
+        // Should not expose UI that lets the user get here.
+        OWSFail(@"%@ Contact editing not supported.", self.tag);
+        return;
+    }
+
+    if (!self.contactsManager.isSystemContactsAuthorized) {
+        [self presentViewController:self.contactsViewHelper.missingContactAccessAlertController
+                           animated:YES
+                         completion:nil];
+        return;
+    }
+
+    OWSAddToContactViewController *viewController = [OWSAddToContactViewController new];
+    [viewController configureWithRecipientId:recipientId];
+    [self.navigationController pushViewController:viewController animated:YES];
+}
+
 - (void)didTapEditButton
 {
     [self presentContactViewController];