Fixes #93 : withFragment() deviates from PSR-7

Author: samsonasik

src/Uri.php

@@ -627,7 +627,7 @@ private function splitQueryValue($value)
     private function filterFragment($fragment)
     {
         if (! empty($fragment) && strpos($fragment, '#') === 0) {
-            $fragment = substr($fragment, 1);
+            $fragment = urlencode('#') . substr($fragment, 1);
         }
 
         return $this->filterQueryOrFragment($fragment);

test/UriTest.php

@@ -331,7 +331,7 @@ public function testStripsFragmentPrefixIfPresent()
     {
         $uri = new Uri('http://example.com');
         $new = $uri->withFragment('#/foo/bar');
-        $this->assertEquals('/foo/bar', $new->getFragment());
+        $this->assertEquals('%23/foo/bar', $new->getFragment());
     }
 
     public function standardSchemePortCombinations()