From 6b2c5a74a3037acad90e3bf651847a04ea50d181 Mon Sep 17 00:00:00 2001
From: Karel Vlk <vlk.charles@gmail.com>
Date: Fri, 30 Aug 2024 18:37:00 +0200
Subject: [PATCH] Message->setBody: Clear headers when adding multi-part body

It is undesirable for these headers to remain from a previous single-part call. Solves #265

Signed-off-by: Karel Vlk <vlk.charles@gmail.com>
---
 src/Message.php | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/Message.php b/src/Message.php
index f0e74840..bb2523c2 100644
--- a/src/Message.php
+++ b/src/Message.php
@@ -408,12 +408,11 @@ public function setBody($body)
 
         // Multipart content headers
         if ($this->body->isMultiPart()) {
-            $mime = $this->body->getMime();
-
-            /** @var ContentType $header */
-            $header = $this->getHeaderByName('content-type', ContentType::class);
-            $header->setType('multipart/mixed');
-            $header->addParameter('boundary', $mime->boundary());
+            $this->clearHeaderByName('content-type');
+            $this->clearHeaderByName('content-transfer-encoding');
+            $this->getHeaderByName('content-type', ContentType::class)
+                ->setType('multipart/mixed')
+                ->addParameter('boundary', $this->body->getMime()->boundary());
             return $this;
         }