EnsureAppDataPath should return full path even when skipping path creation

Author: webprofusion-chrisc

src/Certify.Shared/Utils/EnvironmentUtil.cs

@@ -111,7 +111,7 @@ public static string EnsuredAppDataPath(string subDirectory = null, bool skipCre
             {
                 CreateAndApplyRestrictedACL(path);
 
-                if (subDirectory != null)
+                if (!string.IsNullOrEmpty(subDirectory))
                 {
                     parts.Add(subDirectory);
                     path = Path.Combine(parts.ToArray());
@@ -122,6 +122,11 @@ public static string EnsuredAppDataPath(string subDirectory = null, bool skipCre
                     }
                 }
             }
+            else if (!string.IsNullOrEmpty(subDirectory))
+            {
+                parts.Add(subDirectory);
+                path = Path.Combine(parts.ToArray());
+            }
 
             return path;
         }