De 1078 bug with batch email sending for specific case taken from sla…

…ck conversation (#867)

* Fix problem with sending batch email

```
Whenever we use Mailgun API to send emails, and when 'email to' address and 'Reply to' email address are the same, then the recipient variables are not being replaced with the actual values. I have cross checked this with the team and found that Mailgun API is not replacing the notation with actual values in this case.
```

* Fix problem with sending batch email

```
Whenever we use Mailgun API to send emails, and when 'email to' address and 'Reply to' email address are the same, then the recipient variables are not being replaced with the actual values. I have cross checked this with the team and found that Mailgun API is not replacing the notation with actual values in this case.
```

* test change

* test change

.github/workflows/static.yml

@@ -82,7 +82,7 @@ jobs:
  - name: Setup PHP
  uses: shivammathur/setup-php@v2
  with:
- php-version: 8.0
+ php-version: 8.1
  coverage: none
  tools: composer-normalize
 

CHANGELOG.md

@@ -1,6 +1,9 @@
 # Change Log
 
 The change log describes what is "Added", "Removed", "Changed" or "Fixed" between each release.
+## 3.5.9
+- Fixed: bug when params `to` and `reply-to` have the same address
+
 ## 3.5.6
  - Changed: support bool value for method `createMultiple`
 

src/Message/BatchMessage.php

@@ -91,8 +91,9 @@ protected function addRecipient(string $headerName, string $address, array $vari
  if (array_key_exists($headerName, $this->counters['recipients']) && !array_key_exists('id', $variables)) {
  $variables['id'] = $headerName.'_'.$this->counters['recipients'][$headerName];
  }
-
- $this->batchRecipientAttributes[$address] = $variables;
+ if ($variables) {
+ $this->batchRecipientAttributes[$address] = $variables;
+ }
 
  return $this;
  }