Fix iconv_mime_decode(): Detected an illegal character in input string - closes #5265

Author: freescout-help-desk

app/Console/Commands/FetchEmails.php

@@ -713,7 +713,7 @@ public function processMessage($message, $message_id, $mailbox, $mailboxes, $ext
 
             // Convert subject encoding
             if (preg_match('/=\?[a-z\d-]+\?[BQ]\?.*\?=/i', $subject)) {
-                $subject = iconv_mime_decode($subject, ICONV_MIME_DECODE_CONTINUE_ON_ERROR, 'UTF-8');
+                $subject = \Helper::iconvMimeDecode($subject);
             }
 
             $to = $this->formatEmailList($message->getTo());

app/Misc/Helper.php

@@ -2523,4 +2523,16 @@ public static function startsiWith($text, $string)
     {
         return (stripos($text, $string) === 0);
     }
+
+    // The iconv_mime_decode() may throw an error even with ICONV_MIME_DECODE_CONTINUE_ON_ERROR.
+    // https://github.com/freescout-help-desk/freescout/issues/5265
+    public static function iconvMimeDecode($string, $mode = ICONV_MIME_DECODE_CONTINUE_ON_ERROR, $encoding = "UTF-8")
+    {
+        try {
+            return iconv_mime_decode($string, $mode, $encoding);
+        } catch (\Exception $e) {
+            self::logException($e);
+            return $string;
+        }
+    }
 }

app/Misc/Mail.php

@@ -738,7 +738,7 @@ public static function imapUtf8($mime_encoded_text)
         if (function_exists('imap_utf8')) {
             return imap_utf8($mime_encoded_text);
         } else {
-            return iconv_mime_decode($mime_encoded_text, ICONV_MIME_DECODE_CONTINUE_ON_ERROR, "UTF-8");
+            return \Helper::iconvMimeDecode($mime_encoded_text);
         }
     }
 
@@ -1288,7 +1288,7 @@ public static function decodeSubject($subject)
 
         // iconv_mime_decode() can't decode:
         // =?iso-2022-jp?B?IBskQiFaSEcyPDpuQC4wTU1qIVs3Mkp2JSIlLyU3JSItahsoQg==?=
-        $subject_decoded = iconv_mime_decode($subject, ICONV_MIME_DECODE_CONTINUE_ON_ERROR, "UTF-8");
+        $subject_decoded = \Helper::iconvMimeDecode($subject);
 
         // Sometimes iconv_mime_decode() can't decode some parts of the subject:
         // =?iso-2022-jp?B?IBskQiFaSEcyPDpuQC4wTU1qIVs3Mkp2JSIlLyU3JSItahsoQg==?=

overrides/webklex/php-imap/src/Header.php

@@ -570,7 +570,8 @@ private function decode($value) {
                     }
                 }
             } elseif ($decoder === 'iconv') {
-                $value = iconv_mime_decode($value, ICONV_MIME_DECODE_CONTINUE_ON_ERROR, "UTF-8");
+                //$value = iconv_mime_decode($value, ICONV_MIME_DECODE_CONTINUE_ON_ERROR, "UTF-8");
+                $value = \Helper::iconvMimeDecode($value);
             } elseif ($is_utf8_base) {
                 $value = mb_decode_mimeheader($value);
             }