Fix handling empty OPT

lib/Rdata/OPT.php

@@ -98,7 +98,7 @@ public function fromWire(string $rdata, int &$offset = 0, ?int $rdLength = null)
         $rdLength = $rdLength ?? strlen($rdata);
 
         $endOffset = $offset + $rdLength;
-        do {
+        while ($offset < $endOffset) {
             $integers = @unpack('ncode/nlength', $rdata, $offset);
             if (false === $integers) {
                 throw new DecodeException(static::TYPE, $rdata);
@@ -112,6 +112,6 @@ public function fromWire(string $rdata, int &$offset = 0, ?int $rdLength = null)
             }
             $option->fromWire($rdata, $offset, $integers['length']);
             $this->options[] = $option;
-        } while ($offset < $endOffset);
+        }
     }
 }

tests/MessageTest.php

@@ -267,6 +267,16 @@ public function testWire8(): void
         $this->assertEquals($expectation, $msg->toWire());
     }
 
+    public function testWire9(): void
+    {
+        $expectation = $this->getWireTestData(9);
+        $msg = Message::fromWire($this->getWireTestData(9));
+        $additionals = $msg->getAdditionals();
+        $this->assertCount(1, $additionals);
+        $this->assertInstanceOf(OPT::class, $additionals[0]->getRdata());
+        $this->assertEquals($expectation, $msg->toWire());
+    }
+
     public function testWire10(): void
     {
         $this->expectException(UnexpectedValueException::class);

tests/Rdata/OptTest.php

@@ -59,6 +59,15 @@ public function testFromWire2(): void
         $opt->fromWire($wire);
     }
 
+    public function testFromWire3(): void
+    {
+        $wire = '';
+
+        $opt = new OPT();
+        $opt->fromWire($wire);
+        $this->assertCount(0, $opt->getOptions());
+    }
+
     public function testToWire(): void
     {
         $options = [];

tests/Resources/wire/wire_test.data9

@@ -0,0 +1,13 @@
+# HEADER SECTION
+30 99  # ID
+01 20  # FLAGS
+00 01 # QDCOUNT=1
+00 00 # ANCOUNT=0
+00 00 # NSCOUNT=0
+00 01 # ARCOUNT=1
+
+#QUESTION SECTION
+05 67 6f 6f 67 65 03 63 6f 6d 00 00 01 00 01 # question section: google.com IN A
+
+#ADDITIONAL RECORDS
+00 00 29 04 d0 00 00 00 00 00 00