Added empty string checks to XmlParser.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/3.0@3960 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/DisplayBindings/XmlEditor/Project/Src/XmlParser.cs

@@ -118,7 +118,7 @@ namespace ICSharpCode.XmlEditor
 		/// </summary>
 		public static bool IsNamespaceDeclaration(string xml, int index)
 		{
-			if (xml.Length == 0) {
+			if (String.IsNullOrEmpty(xml)) {
 				return false;
 			}
 			
@@ -185,7 +185,7 @@ namespace ICSharpCode.XmlEditor
 		/// </summary>
 		public static string GetAttributeName(string xml, int index)
 		{
-			if (xml.Length == 0) {
+			if (String.IsNullOrEmpty(xml)) {
 				return String.Empty;
 			}
 			
@@ -203,7 +203,7 @@ namespace ICSharpCode.XmlEditor
 		{
 			string name = GetAttributeNameAtIndex(xml, index);
 			QualifiedName qualifiedName = GetQualifiedName(name);
-			if (String.IsNullOrEmpty(qualifiedName.Namespace) && includeNamespace) {
+			if (qualifiedName != null && String.IsNullOrEmpty(qualifiedName.Namespace) && includeNamespace) {
 				QualifiedNameCollection namespaces = new QualifiedNameCollection();
 				XmlElementPath path = GetActiveElementStartPathAtIndex(xml, index, namespaces);
 				qualifiedName.Namespace = GetNamespaceForPrefix(namespaces, path.Elements.LastPrefix);
@@ -226,6 +226,10 @@ namespace ICSharpCode.XmlEditor
 		/// </summary>
 		public static string GetAttributeNameAtIndex(string xml, int index)
 		{
+			if (String.IsNullOrEmpty(xml)) {
+				return String.Empty;
+			}
+			
 			index = GetCorrectedIndex(xml.Length, index);
 			
 			bool ignoreWhitespace = true;
@@ -308,7 +312,7 @@ namespace ICSharpCode.XmlEditor
 		/// </summary>
 		public static bool IsInsideAttributeValue(string xml, int index)
 		{
-			if (xml.Length == 0) {
+			if (String.IsNullOrEmpty(xml)) {
 				return false;
 			}
 			

src/AddIns/DisplayBindings/XmlEditor/Test/Parser/AttributeNameTestFixture.cs

@@ -114,6 +114,31 @@ namespace XmlEditor.Tests.Parser
 			QualifiedName name = XmlParser.GetQualifiedAttributeName(text, text.Length);
 			Assert.AreEqual(expectedName, name);
 		}
+		
+		[Test]
+		public void GetQualifiedAttributeNameWithEmptyString()
+		{
+			Assert.IsNull(XmlParser.GetQualifiedAttributeNameAtIndex(String.Empty, 0, true));
+		}
+		
+		[Test]
+		public void GetAttributeNameAtIndexWithNullString()
+		{
+			Assert.AreEqual(String.Empty, XmlParser.GetAttributeNameAtIndex(null, 0));
+		}
+		
+		[Test]
+		public void GetAttributeNameWithNullString()
+		{
+			Assert.AreEqual(String.Empty, XmlParser.GetAttributeName(null, 0));
+		}		
+		
+		
+		[Test]
+		public void GetQualifiedAttributeNameWithSingleXmlCharacter()
+		{
+			Assert.IsNull(XmlParser.GetQualifiedAttributeNameAtIndex("<", 0, true));
+		}		
 	}
 }
 

src/AddIns/DisplayBindings/XmlEditor/Test/Parser/InsideAttributeValueTestFixture.cs

@@ -104,5 +104,11 @@ namespace XmlEditor.Tests.Parser
 			string xml = "<foo a=\"''\"";
 			Assert.IsFalse(XmlParser.IsInsideAttributeValue(xml, xml.Length));
 		}
+		
+		[Test]
+		public void NullString()
+		{
+			Assert.IsFalse(XmlParser.IsInsideAttributeValue(null, 0));
+		}
 	}
 }

src/AddIns/DisplayBindings/XmlEditor/Test/Parser/NamespaceDeclarationTestFixture.cs

@@ -116,5 +116,11 @@ namespace XmlEditor.Tests.Parser
 			bool isNamespace = XmlParser.IsNamespaceDeclaration(text, text.Length);
 			Assert.IsFalse(isNamespace, "Namespace should not be recognised.");
 		}
+		
+		[Test]
+		public void NullString()
+		{
+			Assert.IsFalse(XmlParser.IsNamespaceDeclaration(null, 0));
+		}
 	}
 }