Don't notify for some error messages

Specifically:

- Don't play alert when building block offer

- Don't play/show redundant alert/lockscreen notifications for id changes
  e.g.: if you share 100 groups with Bob, and Bob's SN change, you only
  need *one* notification, even though we display the message in 100
  group threads + 1 contact thread.

// FREEBIE

src/Messages/Interactions/TSErrorMessage.m

@@ -5,7 +5,6 @@
 #import "TSErrorMessage.h"
 #import "ContactsManagerProtocol.h"
 #import "NSDate+millisecondTimeStamp.h"
-#import "NotificationsProtocol.h"
 #import "TSContactThread.h"
 #import "TSErrorMessage_privateConstructor.h"
 #import "TSMessagesManager.h"
@@ -46,15 +45,6 @@ NS_ASSUME_NONNULL_BEGIN
     _errorType = errorMessageType;
     _recipientId = recipientId;
 
-    // TODO: Move this out of model class.
-    //
-    //       For now, dispatch async to ensure we're not inside a transaction
-    //       and thereby avoid deadlock.
-    TSErrorMessage *errorMessage = self;
-    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
-        [[TextSecureKitEnv sharedEnv].notificationsManager notifyUserForErrorMessage:errorMessage inThread:thread];
-    });
-
     return self;
 }
 

src/Messages/TSMessagesManager.m

@@ -333,6 +333,7 @@ NS_ASSUME_NONNULL_BEGIN
                     TSErrorMessage *errorMessage =
                         [TSErrorMessage missingSessionWithEnvelope:messageEnvelope withTransaction:transaction];
                     [errorMessage saveWithTransaction:transaction];
+                    [self notififyForErrorMessage:errorMessage withEnvelope:messageEnvelope];
                 }];
                 DDLogError(@"Skipping message envelope for unknown session.");
                 completion(nil);
@@ -974,9 +975,9 @@ NS_ASSUME_NONNULL_BEGIN
         exception.description,
         exception.name,
         exception.reason);
-    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-      TSErrorMessage *errorMessage;
 
+    __block TSErrorMessage *errorMessage;
+    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
       if ([exception.name isEqualToString:NoSessionException]) {
           errorMessage = [TSErrorMessage missingSessionWithEnvelope:envelope withTransaction:transaction];
       } else if ([exception.name isEqualToString:InvalidKeyException]) {
@@ -997,6 +998,16 @@ NS_ASSUME_NONNULL_BEGIN
 
       [errorMessage saveWithTransaction:transaction];
     }];
+
+    if (errorMessage != nil) {
+        [self notififyForErrorMessage:errorMessage withEnvelope:envelope];
+    }
+}
+
+- (void)notififyForErrorMessage:(TSErrorMessage *)errorMessage withEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
+{
+    TSThread *contactThread = [TSContactThread getOrCreateThreadWithContactId:envelope.source];
+    [[TextSecureKitEnv sharedEnv].notificationsManager notifyUserForErrorMessage:errorMessage inThread:contactThread];
 }
 
 #pragma mark - helpers

src/Storage/AxolotlStore/TSStorageManager+IdentityKeyStore.m

@@ -3,6 +3,8 @@
 //
 
 #import "NSDate+millisecondTimeStamp.h"
+#import "NotificationsProtocol.h"
+#import "OWSRecipientIdentity.h"
 #import "TSAccountManager.h"
 #import "TSContactThread.h"
 #import "TSErrorMessage.h"
@@ -11,7 +13,6 @@
 #import "TSStorageManager+IdentityKeyStore.h"
 #import "TSStorageManager+SessionStore.h"
 #import "TextSecureKitEnv.h"
-#import "OWSRecipientIdentity.h"
 #import <25519/Curve25519.h>
 
 NS_ASSUME_NONNULL_BEGIN
@@ -266,7 +267,11 @@ const NSTimeInterval kIdentityKeyStoreNonBlockingSecondsThreshold = 5.0;
     TSContactThread *contactThread = [TSContactThread getOrCreateThreadWithContactId:recipientId];
     OWSAssert(contactThread != nil);
 
-    [[TSErrorMessage nonblockingIdentityChangeInThread:contactThread recipientId:recipientId] save];
+    TSErrorMessage *errorMessage =
+        [TSErrorMessage nonblockingIdentityChangeInThread:contactThread recipientId:recipientId];
+    [errorMessage save];
+
+    [[TextSecureKitEnv sharedEnv].notificationsManager notifyUserForErrorMessage:errorMessage inThread:contactThread];
 
     for (TSGroupThread *groupThread in [TSGroupThread groupThreadsWithRecipientId:recipientId]) {
         [[TSErrorMessage nonblockingIdentityChangeInThread:groupThread recipientId:recipientId] save];