[Boost-bugs] [Boost C++ Libraries] #10900: read_symlink fails to correctly read NTFS junctions

Subject: [Boost-bugs] [Boost C++ Libraries] #10900: read_symlink fails to correctly read NTFS junctions
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-12-26 16:16:26

#10900: read_symlink fails to correctly read NTFS junctions
------------------------------------------------+------------------------
 Reporter:  Benjamin Kummer-Hardt <benjamin@…>  |      Owner:  bemandawes
     Type:  Bugs                                |     Status:  new
Milestone:  To Be Determined                    |  Component:  filesystem
  Version:  Boost 1.57.0                        |   Severity:  Problem
 Keywords:                                      |
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 ''Tested on Windows 7 64-bit.''

 NTFS directory junctions are now recognized as a symlink by
 `is_reparse_point_a_symlink` but `read_symlink` does not correctly handle
 those "mount point" reparse points yet.

 Among other things this also breaks the `canonical` operation.

 The `REPARSE_DATA_BUFFER` returned by `DeviceIoControl` needs to be
 accessed differently for regular symlinks and mount points. See
 msdn.microsoft.com/en-us/library/ff552012.aspx

 Accessing the "!PrintName" as a symlink typically results in the first two
 (wide) characters of the path being skipped and generally in undefined
 behavior.

 A possible fix would be to add a conditional statement checking
 `info.rdb.ReparseTag == IO_REPARSE_TAG_MOUNT_POINT` and then amend the
 `symlink_path.assign` call accordingly (using
 `info.rdb.MountPointReparseBuffer` instead of
 `info.rdb.SymbolicLinkReparseBuffer`).

 In version 1.57.0 the offending code can be found in
 ''libs/filesystem/src/operations.cpp'' around line 1514.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10900>
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