Fix observed mismatches by swapping in original UUID

service/src/main/java/org/whispersystems/textsecuregcm/storage/AccountsManager.java

@@ -118,12 +118,25 @@ public class AccountsManager {
 
   public boolean create(Account account) {
     try (Timer.Context ignored = createTimer.time()) {
+      final UUID originalUuid = account.getUuid();
       boolean freshUser = databaseCreate(account);
-      redisSet(account);
 
+      // databaseCreate() sometimes updates the UUID, if there was a number conflict.
+      // for metrics, we want dynamo to run with the same original UUID
+      final UUID actualUuid = account.getUuid();
+
+      try {
         if (dynamoWriteEnabled()) {
+
+          account.setUuid(originalUuid);
+
           runSafelyAndRecordMetrics(() -> dynamoCreate(account), Optional.of(account.getUuid()), freshUser,
               (databaseResult, dynamoResult) -> {
+
+                if (!account.getUuid().equals(actualUuid)) {
+                  logger.warn("dynamoCreate() did not return correct UUID");
+                }
+
                 if (databaseResult.equals(dynamoResult)) {
                   return Optional.empty();
                 }
@@ -136,6 +149,12 @@ public class AccountsManager {
               },
               "create");
         }
+      } finally {
+        account.setUuid(actualUuid);
+      }
+
+      redisSet(account);
+
       return freshUser;
     }
   }