Fix setEof/setFileTime exceptions (#16)

* Fixed Exception when setEof is called on not yet opened file

* Fixed Exception on setFileTime on currently opened file

* Cleanup

DokanPbo.Core/PboFS.cs

@@ -97,7 +97,7 @@ private void DeleteNode(string filename)
 
         private IPboFsNode GetNodeFast(string filename, DokanFileInfo info)
         {
-            if (info.Context is IPboFsNode node)
+            if (info?.Context is IPboFsNode node)
                 return node;
             return FindNode(filename);
         }
@@ -564,6 +564,8 @@ public NtStatus SetFileTime(string filename, DateTime? ctime, DateTime? atime, D
 
             if (node is PboFsRealFile file)
             {
+                //#TODO we can't do this while file is open. Optimally we just want to queue tasks to be executed once the file is closed.
+                if (file.IsOpenForWriting) return DokanResult.Success;
                 if (ctime != null)
                 {
                     System.IO.File.SetCreationTime(file.GetRealPath(), ctime.Value);

DokanPbo.Core/PboFSNode.cs

@@ -1,4 +1,4 @@
-using DokanNet;
+using DokanNet;
 using SwiftPbo;
 using System;
 using System.Collections.Generic;
@@ -277,9 +277,10 @@ public class PboFsRealFile : IPboFsFile, IPboFsRealObject
     {
         public System.IO.FileInfo file;
         private bool? wantsOpenWrite;
-        private FileMode openMode;
+        private FileMode openMode = FileMode.Open;
         private System.IO.FileStream readStream = null;
         private System.IO.FileStream writeStream = null;
+        public bool IsOpenForWriting => writeStream != null;
 
         //In case someone tries to set lastWriteTime while we have a Write stream open.
         private DateTime? lastWriteTimeTodo;
@@ -300,6 +301,7 @@ public PboFsRealFile(System.IO.FileInfo inputFile, PboFsFolder inputParent) : ba
             };
         }
 
+        //writeableStream is from newly created file
         public PboFsRealFile(System.IO.FileInfo inputFile, PboFsFolder inputParent, System.IO.FileStream writeableStream) : this(inputFile, inputParent)
         {
             writeStream = writeableStream;