`GetLongPathName()` function may fail when it is unable to query
the parent directory of a path component to determine the long name
for that component. It happens, because it uses `FindFirstFile()`
function for each next short part of path. The `FindFirstFile()`
requires `List Directory` and `Synchronize` desired access for a calling
process.
In case of lacking such permission for some part of path,
the `GetLongPathName()` returns 0 as result and `GetLastError()`
returns ERROR_ACCESS_DENIED.
`GetFinalPathNameByHandle()` function can help in such cases, because
it requires `Read Attributes` and `Synchronize` desired access to the
target path only.
The `GetFinalPathNameByHandle()` function was introduced on
`Windows Server 2008/Windows Vista`. So we need to load it dynamically.
`CreateFile()` parameters:
`lpFileName` = path to the current directory
`dwDesiredAccess` = 0 (it means `Read Attributes` and `Synchronize`)
`dwShareMode` = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE
(it prevents `Sharing Violation`)
`lpSecurityAttributes` = NULL (default security attributes)
`dwCreationDisposition` = OPEN_EXISTING
(required to obtain a directory handle)
`dwFlagsAndAttributes` = FILE_FLAG_BACKUP_SEMANTICS
(required to obtain a directory handle)
`hTemplateFile` = NULL (when opening an existing file or directory,
`CreateFile` ignores this parameter)
The string that is returned by `GetFinalPathNameByHandle()` function
uses the \\?\ syntax. To skip the prefix and convert backslashes
to slashes, the `normalize_ntpath()` mingw function will be used.
Note: `GetFinalPathNameByHandle()` function returns a final path.
It is the path that is returned when a path is fully resolved.
For example, for a symbolic link named "C:\tmp\mydir" that points to
"D:\yourdir", the final path would be "D:\yourdir".
Signed-off-by: Anton Serbulov <aserbulov@plesk.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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