Merge pull request #21 from jbrayfaithlife/issue/#20

Auto-identify the XML namespace Issue 20

Author: FlorianRappl

src/AngleSharp.Xml.Tests/Parser/XmlParsing.cs

@@ -146,5 +146,13 @@ public void ParseInvalidXmlShouldNotThrowWhenSuppressingErrors_Issue14()
                 parser.ParseDocument(source);
             });
         }
+
+        [Test]
+        public async Task XmlPrefixedAttributesShouldLocateXmlNamespaceWithoutDeclaration()
+        {
+            var document = @"<xml xml:lang=""en""></xml>".ToXmlDocument();
+            var root = document.DocumentElement;
+            Assert.AreEqual(NamespaceNames.XmlUri, root.Attributes.Single().NamespaceUri);
+        }
     }
 }

src/AngleSharp.Xml/Parser/XmlDomBuilder.cs

@@ -431,7 +431,11 @@ private Attr CreateAttribute(String name, String value)
                 var prefix = name.Substring(0, colon);
                 var ns = NamespaceNames.XmlNsUri;
 
-                if (!prefix.Is(NamespaceNames.XmlNsPrefix))
+                if (prefix.Is(NamespaceNames.XmlPrefix))
+                {
+                    ns = NamespaceNames.XmlUri;
+                }
+                else if (!prefix.Is(NamespaceNames.XmlNsPrefix))
                 {
                     ns = CurrentNode.LookupNamespaceUri(prefix);
                 }