Merge pull request #103 from sunsided/pull-requests/containsattribute-nullref

fixed NullReferenceException when _styles is not set

Source/SvgElement.cs

@@ -77,7 +77,7 @@ namespace Svg
         {
             SortedDictionary<int, string> rules;
             return (this.Attributes.ContainsKey(name) || this.CustomAttributes.ContainsKey(name) ||
-                (_styles.TryGetValue(name, out rules) && (rules.ContainsKey(StyleSpecificity_InlineStyle) || rules.ContainsKey(StyleSpecificity_PresAttribute))));
+                (_styles != null && _styles.TryGetValue(name, out rules)) && (rules.ContainsKey(StyleSpecificity_InlineStyle) || rules.ContainsKey(StyleSpecificity_PresAttribute)));
         }
         public bool TryGetAttribute(string name, out string value)
         {
@@ -89,7 +89,7 @@ namespace Svg
             }
             if (this.CustomAttributes.TryGetValue(name, out value)) return true;
             SortedDictionary<int, string> rules;
-            if (_styles.TryGetValue(name, out rules))
+            if (_styles != null && _styles.TryGetValue(name, out rules))
             {
                 // Get staged styles that are 
                 if (rules.TryGetValue(StyleSpecificity_InlineStyle, out value)) return true;