Merge pull request #2660 from compnerd/nt-paths-to-dos-paths

FileManager: correct symbolic link handling on Windows

Author: compnerd

Foundation/FileManager+Win32.swift

@@ -397,9 +397,17 @@ extension FileManager {
         }
 
         let substituteNameBuff = Data(bytes: pathBufferPtr + substituteNameOffset, count: substituteNameBytes)
-        guard let substitutePath = String(data: substituteNameBuff, encoding: .utf16LittleEndian) else {
+        guard var substitutePath = String(data: substituteNameBuff, encoding: .utf16LittleEndian) else {
             throw _NSErrorWithWindowsError(DWORD(ERROR_INVALID_DATA), reading: false)
         }
+
+        // Canonicalize the NT Object Manager Path to the DOS style path
+        // instead.  Unfortunately, there is no nice API which can allow us to
+        // do this in a guranteed way.
+        let kObjectManagerPrefix = "\\??\\"
+        if substitutePath.hasPrefix(kObjectManagerPrefix) {
+          substitutePath = String(substitutePath.dropFirst(kObjectManagerPrefix.count))
+        }
         return substitutePath
     }