Fix inline attachments being broken when only sending an HTML text body.

The rel boundary was closed too early causing inline images to be
incorrectly included in the email message.

Refs #3474

lib/Cake/Network/Email/CakeEmail.php

@@ -1567,7 +1567,7 @@ protected function _render($content) {
 			$msg[] = '';
 		}
 
-		if ($textBoundary !== $boundary) {
+		if ($textBoundary !== $relBoundary) {
 			$msg[] = '--' . $textBoundary . '--';
 			$msg[] = '';
 		}

lib/Cake/Test/Case/Network/Email/CakeEmailTest.php

@@ -1167,6 +1167,48 @@ public function testSendWithInlineAttachments() {
 		$this->assertContains('--' . $boundary . '--', $result['message']);
 	}
 
+/**
+ * Test setting inline attachments and HTML only messages.
+ *
+ * @return void
+ */
+	public function testSendWithInlineAttachmentsHtmlOnly() {
+		$this->CakeEmail->transport('debug');
+		$this->CakeEmail->from('cake@cakephp.org');
+		$this->CakeEmail->to('cake@cakephp.org');
+		$this->CakeEmail->subject('My title');
+		$this->CakeEmail->emailFormat('html');
+		$this->CakeEmail->attachments(array(
+			'cake.png' => array(
+				'file' => CAKE . 'VERSION.txt',
+				'contentId' => 'abc123'
+			)
+		));
+		$result = $this->CakeEmail->send('Hello');
+
+		$boundary = $this->CakeEmail->getBoundary();
+		$this->assertContains('Content-Type: multipart/mixed; boundary="' . $boundary . '"', $result['headers']);
+		$expected = "--$boundary\r\n" .
+			"Content-Type: multipart/related; boundary=\"rel-$boundary\"\r\n" .
+			"\r\n" .
+			"--rel-$boundary\r\n" .
+			"Content-Type: text/html; charset=UTF-8\r\n" .
+			"Content-Transfer-Encoding: 8bit\r\n" .
+			"\r\n" .
+			"Hello" .
+			"\r\n" .
+			"\r\n" .
+			"\r\n" .
+			"--rel-$boundary\r\n" .
+			"Content-Type: application/octet-stream\r\n" .
+			"Content-Transfer-Encoding: base64\r\n" .
+			"Content-ID: <abc123>\r\n" .
+			"Content-Disposition: inline; filename=\"cake.png\"\r\n\r\n";
+		$this->assertContains($expected, $result['message']);
+		$this->assertContains('--rel-' . $boundary . '--', $result['message']);
+		$this->assertContains('--' . $boundary . '--', $result['message']);
+	}
+
 /**
  * Test disabling content-disposition.
  *