From f9448e4613578dd17106cc3189931c59a32cbc1a Mon Sep 17 00:00:00 2001
From: morkt <muvluv.ru@gmail.com>
Date: Tue, 22 Sep 2015 22:39:10 +0400
Subject: [PATCH] fixed filesystem traversal.

---
 GameRes/FileSystem.cs | 33 ++++++++++++---------------------
 MainWindow.xaml.cs    |  3 +++
 2 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/GameRes/FileSystem.cs b/GameRes/FileSystem.cs
index 3f5ee865..a0789d99 100644
--- a/GameRes/FileSystem.cs
+++ b/GameRes/FileSystem.cs
@@ -582,31 +582,22 @@ namespace GameRes
                 if (!value.Any())
                     return;
                 var desired = value.ToArray();
-                if (desired.Length == Count)
+                int desired_vfs_count = desired.Length;
+                var arc_iterator = m_vfs.ArcStack.Reverse().GetEnumerator();
+                int i = 0;
+                while (i < desired_vfs_count - 1 && arc_iterator.MoveNext())
                 {
-                    var cur_stack = m_vfs.ArcStack.Reverse();
-                    if (1 == Count || cur_stack.SequenceEqual (desired.Take (desired.Length-1)))
-                    {
-                        // desired path is identical to current, adjust final component only
-                        m_vfs.Top.CurrentDirectory = desired.Last();
-                        return;
-                    }
+                    if (arc_iterator.Current != desired[i])
+                        break;
+                    ++i;
                 }
-                // desired path is different, rebuild filesystem hierarchy from scratch
-                var new_vfs = new FileSystemStack();
-                try
+                while (Count > i+1)
+                    m_vfs.Pop();
+                while (Count < desired_vfs_count)
                 {
-                    for (int i = 0; i < desired.Length-1; ++i)
-                        new_vfs.ChDir (new_vfs.Top.FindFile (desired[i]));
-                    new_vfs.Top.CurrentDirectory = desired.Last();
-                    m_vfs.Dispose();
+                    m_vfs.ChDir (m_vfs.Top.FindFile (desired[Count-1]));
                 }
-                catch
-                {
-                    new_vfs.Dispose();
-                    throw;
-                }
-                m_vfs = new_vfs;
+                m_vfs.Top.CurrentDirectory = desired.Last();
             }
         }
 
diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
index 1ed13070..6df8556a 100644
--- a/MainWindow.xaml.cs
+++ b/MainWindow.xaml.cs
@@ -685,6 +685,9 @@ namespace GARbro.GUI
             }
             catch (Exception X)
             {
+                // if VFS.FullPath throws an exception, ViewModel becomes inconsistent at this point
+                // and should be rebuilt
+                ViewModel = CreateViewModel (VFS.Top.CurrentDirectory, true);
                 SetStatusText (X.Message);
                 return false;
             }