Use also Envelope-To for identity selection (#1488553)

CHANGELOG

@@ -8,7 +8,7 @@ CHANGELOG Roundcube Webmail
 - Fix broken message/part bodies when FETCH response contains more untagged lines (#1488836)
 - Fix empty email on identities list after identity update (#1488834)
 - Add new identities_level: (4) one identity with possibility to edit only signature
-- Use Delivered-To header as a last resort for identity selection (#1488840)
+- Use Delivered-To and Envelope-To headers for identity selection (#1488840, #1488553)
 - Fix XSS vulnerability using Flash files (#1488828)
 - Fix absolute positioning in HTML messages (#1488819)
 - Fix cache (in)validation after setting \Deleted flag

program/lib/Roundcube/rcube_storage.php

@@ -65,6 +65,7 @@ abstract class rcube_storage
         'MAIL-REPLY-TO',
         'RETURN-PATH',
         'DELIVERED-TO',
+        'ENVELOPE-TO',
     );
 
     const UNKNOWN       = 0;

program/steps/mail/compose.inc

@@ -455,6 +455,16 @@ function rcmail_identity_select($MESSAGE, $identities, $compose_mode)
     }
   }
 
+  // Fallback using Envelope-To
+  if ($from_idx === null && ($envelope_to = $MESSAGE->headers->others['envelope-to'])) {
+    foreach ($identities as $idx => $ident) {
+      if (in_array($ident['email_ascii'], (array)$envelope_to)) {
+        $from_idx = $idx;
+        break;
+      }
+    }
+  }
+
   return $identities[$from_idx !== null ? $from_idx : $default_identity];
 }