Allow 'Received' hostnames without '.' chars #104

src/Header/Consumer/Received/DomainConsumer.php

@@ -23,16 +23,15 @@
  * The parenthesized part normally (but not necessarily) following a name must
  * "look like" a tcp-info section of an extended domain as defined by RFC5321.
  * The validation is very purposefully very loose to be accommodating to many
- * erroneous implementations.  Strictly speaking, a domain part, if it exists,
- * must start with an alphanumeric character.  There must be at least one '.' in
- * the domain part, followed by any number of more alphanumeric, '.', and '-'
- * characters.  The address part must be within square brackets, '[]'...
- * although an address outside of square brackets could be matched by the domain
- * matcher if it exists alone within the parentheses.  The address, strictly
- * speaking, is any number of '.', numbers, ':' and letters a-f.  This allows it
- * to match ipv6 addresses as well.  In addition, the address may start with the
- * string "ipv6", and may be followed by a port number as some implementations
- * seem to do.
+ * erroneous implementations.  The only restriction is the host part must
+ * contain two characters, the first being alphanumeric, followed by any number
+ * of more alphanumeric, '.', and '-' characters.  The address part must be
+ * within square brackets, '[]'... although an address outside of square
+ * brackets could be matched by the domain matcher if it exists alone within the
+ * parentheses.  The address is any number of '.', numbers, ':' and letters a-f.
+ * This allows it to match ipv6 addresses as well.  In addition, the address may
+ * start with the string "ipv6", and may be followed by a port number as some
+ * implementations seem to do.
  *
  * Strings in parentheses not matching the aforementioned 'domain/address'
  * pattern will be considered comments, and will be returned as a separate
@@ -67,7 +66,7 @@ protected function isEndToken(string $token) : bool
     private function matchHostPart(string $value, ?string &$hostname, ?string &$address) : bool
     {
         $matches = [];
-        $pattern = '~^(\[(IPv[64])?(?P<addr1>[a-f\d\.\:]+)\])?\s*(helo=)?(?P<name>[a-z0-9\-]+\.[a-z0-9\-\.]+)?\s*(\[(IPv[64])?(?P<addr2>[a-f\d\.\:]+)\])?$~i';
+        $pattern = '~^(\[(IPv[64])?(?P<addr1>[a-f\d\.\:]+)\])?\s*(helo=)?(?P<name>[a-z0-9\-]+[a-z0-9\-\.]+)?\s*(\[(IPv[64])?(?P<addr2>[a-f\d\.\:]+)\])?$~i';
         if (\preg_match($pattern, $value, $matches)) {
             if (!empty($matches['name'])) {
                 $hostname = $matches['name'];

tests/MailMimeParser/Header/Consumer/Received/DomainConsumerTest.php

@@ -49,12 +49,12 @@ public function testConsumeParts() : void
             ['hello ([2001:0db8:85a3:0000:0000:8a2e:0370:7334])', ['ehloName' => 'hello', 'address' => '2001:0db8:85a3:0000:0000:8a2e:0370:7334'], []],
             ['hello', ['ehloName' => 'hello'], []],
             ['hello (blah.blooh [1.2.3.4]) (TEST)', ['ehloName' => 'hello', 'hostname' => 'blah.blooh', 'address' => '1.2.3.4'], []],
-            ['hello (TEST)', ['ehloName' => 'hello'], ['TEST']],
-            ['(blah.blooh)', ['hostname' => 'blah.blooh'], []],
+            ['(blah-blooh)', ['hostname' => 'blah-blooh'], []],
             ['hello ([1.2.3.4] blah.blooh)', ['ehloName' => 'hello', 'hostname' => 'blah.blooh', 'address' => '1.2.3.4'], []],
             ['hello ([1.2.3.4] helo=blah.blooh)', ['ehloName' => 'hello', 'hostname' => 'blah.blooh', 'address' => '1.2.3.4'], []],
             ['hello (helo=blah.blooh [1.2.3.4])', ['ehloName' => 'hello', 'hostname' => 'blah.blooh', 'address' => '1.2.3.4'], []],
-            ['(negatron)', [], ['negatron']],
+            ['(negatron)', ['hostname' => 'negatron'], []],
+            ['(.negatron)', [], ['.negatron']],
         ];
 
         foreach ($aTests as $test) {