GH-450 Browser - Fix for authority to make sure we get the port.

Tests/Browser_Tests.cs

@@ -25,6 +25,8 @@ public async Task Open_Uri_Launch_NetStandard() =>
 
         [Theory]
         [InlineData("https://xamarin.com", "https://xamarin.com")]
+        [InlineData("https://xamarin.com/test.html", "https://xamarin.com/test.html")]
+        [InlineData("https://xamarin.com:56/test.html", "https://xamarin.com:56/test.html")]
         [InlineData("http://xamarin.com", "http://xamarin.com")]
         [InlineData("https://xamariñ.com", "https://xn--xamari-1wa.com")]
         [InlineData("http://xamariñ.com", "http://xn--xamari-1wa.com")]

Xamarin.Essentials/Browser/Browser.shared.cs

@@ -30,7 +30,7 @@ internal static Uri EscapeUri(Uri uri)
             return uri;
 #else
             var idn = new System.Globalization.IdnMapping();
-            return new Uri(uri.Scheme + "://" + idn.GetAscii(uri.DnsSafeHost) + uri.PathAndQuery);
+            return new Uri(uri.Scheme + "://" + idn.GetAscii(uri.Authority) + uri.PathAndQuery);
 #endif
         }
     }