Move more code to PathHelpers

Also fix bug where IsPathTooLong would say "no" for paths exactly
260 characters long (260 *is* too long).

src/Core/Files/FullPath.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
 
 namespace VsChromium.Core.Files {
   /// <summary>
@@ -45,7 +44,7 @@ public FullPath Parent {
     /// <summary>
     /// Return the file name part of this full path.
     /// </summary>
-    public string FileName { get { return Path.GetFileName(_path); } }
+    public string FileName { get { return PathHelpers.GetFileName(_path); } }
 
     /// <summary>
     /// Returns a full path instance as the combination of this full path with
@@ -113,7 +112,7 @@ public bool StartsWith(FullPath x) {
     /// one of its component, i.e. parts between directory separator.
     /// </summary>
     public bool HasComponent(string component) {
-      foreach (string currentComponent in _path.Split(Path.DirectorySeparatorChar)) {
+      foreach (string currentComponent in PathHelpers.SplitPath(_path)) {
         if (currentComponent.Equals(component, StringComparison.CurrentCultureIgnoreCase))
           return true;
       }
@@ -124,7 +123,7 @@ public bool HasComponent(string component) {
     /// Returns the enumeration of the parent full path of this full path.
     /// </summary>
     public IEnumerable<FullPath> EnumerateParents() {
-      for (var parent = this.Parent; parent != default(FullPath); parent = parent.Parent) {
+      for (var parent = Parent; parent != default(FullPath); parent = parent.Parent) {
         yield return parent;
       }
     }

src/Core/Files/PathHelpers.cs

@@ -14,6 +14,7 @@ public static class PathHelpers {
     private static readonly string DirectorySeparatorString = new string(Path.DirectorySeparatorChar, 1);
     private static readonly char[] DirectorySeparatorArray = { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };
     private static readonly string NetworkSharePrefix = new string(Path.DirectorySeparatorChar, 2);
+    public static char DirectorySeparatorChar = Path.DirectorySeparatorChar;
 
     /// <summary>
     /// Combines two paths into a single path. More efficient than <see
@@ -174,7 +175,7 @@ public static bool IsPathTooLong(string parentPath, string relativePath) {
       if (string.IsNullOrEmpty(relativePath))
         return IsPathTooLong(parentPath);
 
-      return parentPath.Length + 1 + relativePath.Length > MaxPath;
+      return (parentPath.Length + 1 + relativePath.Length) >= MaxPath;
     }
 
     /// <summary>
@@ -194,6 +195,20 @@ public static bool IsValidBclPath(string path) {
         return false;
       }
     }
+
+    public static string GetFileName(string path) {
+      if (string.IsNullOrEmpty(path)) {
+        return path;
+      }
+      int length = path.Length;
+      int index = length;
+      while (--index >= 0) {
+        char ch = path[index];
+        if (ch == Path.DirectorySeparatorChar || ch == Path.AltDirectorySeparatorChar || ch == Path.VolumeSeparatorChar)
+          return path.Substring(index + 1, length - index - 1);
+      }
+      return path;
+    }
   }
 
   /// <summary>

src/Core/Files/RelativePath.cs

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 using System;
-using System.IO;
 
 namespace VsChromium.Core.Files {
   /// <summary>
@@ -62,7 +61,7 @@ private static string ExtractFileName(string relativePath) {
         throw new ArgumentNullException("relativePath");
       if (PathHelpers.IsFileName(relativePath))
         return relativePath;
-      return Path.GetFileName(relativePath);
+      return PathHelpers.GetFileName(relativePath);
     }
 
     /// <summary>
@@ -105,28 +104,28 @@ public RelativePath Parent {
     }
 
     public override string ToString() {
-      return this.Value;
+      return Value;
     }
 
     /// <summary>
     /// Returns a new relative path instance by appending <paramref name="name"/> to this instance.
     /// </summary>
     public RelativePath CreateChild(string name) {
-      return new RelativePath(PathHelpers.CombinePaths(this.Value, name), name);
+      return new RelativePath(PathHelpers.CombinePaths(Value, name), name);
     }
 
     #region Comparison/Equality plumbing
 
     public int CompareTo(RelativePath other) {
-      return SystemPathComparer.Instance.StringComparer.Compare(this.Value, other.Value);
+      return SystemPathComparer.Instance.StringComparer.Compare(Value, other.Value);
     }
 
     public bool Equals(RelativePath other) {
-      return SystemPathComparer.Instance.StringComparer.Equals(this.Value, other.Value);
+      return SystemPathComparer.Instance.StringComparer.Equals(Value, other.Value);
     }
 
     public override int GetHashCode() {
-      return SystemPathComparer.Instance.StringComparer.GetHashCode(this.Value);
+      return SystemPathComparer.Instance.StringComparer.GetHashCode(Value);
     }
 
     public override bool Equals(object other) {

src/Server/FileSystem/FileSystemNameFactoryExtensions.cs

@@ -5,7 +5,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.IO;
 using System.Linq;
 using VsChromium.Core.Files;
 using VsChromium.Core.Ipc.TypedMessages;