Add tests for bug found in settings parser.

Author: jonathangreen

tests/Syn/SettingsParserSiteTest.php

@@ -250,6 +250,27 @@ public function testRsaBadEncoding()
 -----END PUBLIC KEY-----
   </site>
 </sites>
+STRING;
+        $logger = $this->prophesize(AbstractLogger::class)->reveal();
+        $parser = new SettingsParser($testXml, $logger);
+        $sites = $parser->getSites();
+        $this->assertEquals(0, count($sites));
+    }
+
+    public function testEmptyString()
+    {
+        $testXml =  <<<STRING
+STRING;
+        $logger = $this->prophesize(AbstractLogger::class)->reveal();
+        $parser = new SettingsParser($testXml, $logger);
+        $sites = $parser->getSites();
+        $this->assertEquals(0, count($sites));
+    }
+
+    public function testIncorrectTags()
+    {
+        $testXml =  <<<STRING
+<foo></foo>
 STRING;
         $logger = $this->prophesize(AbstractLogger::class)->reveal();
         $parser = new SettingsParser($testXml, $logger);