Add Content-Location attachment header support

src/PHPMailer.php

@@ -60,6 +60,9 @@ class PHPMailer
  const ICAL_METHOD_COUNTER = 'COUNTER';
  const ICAL_METHOD_DECLINECOUNTER = 'DECLINECOUNTER';
 
+ const CONTENT_ID = 'Content-ID';
+ const CONTENT_LOCATION = 'Content-Location';
+
  /**
  * Email priority.
  * Options: null (default), 1 = High, 3 = Normal, 5 = low.
@@ -3292,6 +3295,7 @@ public function addAttachment(
  5 => false, //isStringAttachment
  6 => $disposition,
  7 => $name,
+ 8 => static::CONTENT_ID,
  ];
  } catch (Exception $exc) {
  $this->setError($exc->getMessage());
@@ -3358,6 +3362,7 @@ protected function attachAll($disposition_type, $boundary)
  $type = $attachment[4];
  $disposition = $attachment[6];
  $cid = $attachment[7];
+ $cidType = $attachment[8];
  if ('inline' === $disposition && array_key_exists($cid, $cidUniq)) {
  continue;
  }
@@ -3384,9 +3389,17 @@ protected function attachAll($disposition_type, $boundary)
  $mime[] = sprintf('Content-Transfer-Encoding: %s%s', $encoding, static::$LE);
  }
 
- //Only set Content-IDs on inline attachments
- if ((string) $cid !== '' && $disposition === 'inline') {
- $mime[] = 'Content-ID: <' . $this->encodeHeader($this->secureHeader($cid)) . '>' . static::$LE;
+ //Only set Content-ID/Content-Location headers on inline attachments
+ if (
+ (string) $cid !== ''
+ && $disposition === 'inline'
+ && in_array($cidType, [static::CONTENT_ID, static::CONTENT_LOCATION], true)
+ ) {
+ $encodedCid = $this->encodeHeader($this->secureHeader($cid));
+ if ($cidType === static::CONTENT_ID) {
+ $encodedCid = '<' . $encodedCid . '>';
+ }
+ $mime[] = $cidType . ': ' . $encodedCid . static::$LE;
  }
 
  //Allow for bypassing the Content-Disposition header
@@ -3782,6 +3795,7 @@ public function addStringAttachment(
  5 => true, //isStringAttachment
  6 => $disposition,
  7 => 0,
+ 8 => '',
  ];
  } catch (Exception $exc) {
  $this->setError($exc->getMessage());
@@ -3813,6 +3827,7 @@ public function addStringAttachment(
  * @param string $type File MIME type (by default mapped from the `$path` filename's extension)
  * @param string $disposition Disposition to use: `inline` (default) or `attachment`
  * (unlikely you want this – {@see `addAttachment()`} instead)
+ * @param string $cidType static::CONTENT_ID (default) or static::CONTENT_LOCATION
  *
  * @return bool True on successfully adding an attachment
  * @throws Exception
@@ -3824,7 +3839,8 @@ public function addEmbeddedImage(
  $name = '',
  $encoding = self::ENCODING_BASE64,
  $type = '',
- $disposition = 'inline'
+ $disposition = 'inline',
+ $cidType = self::CONTENT_ID
  ) {
  try {
  if (!static::fileIsAccessible($path)) {
@@ -3855,6 +3871,7 @@ public function addEmbeddedImage(
  5 => false, //isStringAttachment
  6 => $disposition,
  7 => $cid,
+ 8 => $cidType,
  ];
  } catch (Exception $exc) {
  $this->setError($exc->getMessage());
@@ -3883,6 +3900,7 @@ public function addEmbeddedImage(
  * @param string $encoding File encoding (see $Encoding), defaults to 'base64'
  * @param string $type MIME type - will be used in preference to any automatically derived type
  * @param string $disposition Disposition to use
+ * @param string $cidType static::CONTENT_ID (default) or static::CONTENT_LOCATION
  *
  * @throws Exception
  *
@@ -3894,7 +3912,8 @@ public function addStringEmbeddedImage(
  $name = '',
  $encoding = self::ENCODING_BASE64,
  $type = '',
- $disposition = 'inline'
+ $disposition = 'inline',
+ $cidType = self::CONTENT_ID
  ) {
  try {
  //If a MIME type is not specified, try to work it out from the name
@@ -3916,6 +3935,7 @@ public function addStringEmbeddedImage(
  5 => true, //isStringAttachment
  6 => $disposition,
  7 => $cid,
+ 8 => $cidType,
  ];
  } catch (Exception $exc) {
  $this->setError($exc->getMessage());