Use GetFinalPathNameByHandleW instead of GetLongPathNameW to get full path #606
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skvoboo
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The string that is returned by |
I know that, thanks.
This is not a good explanation! It states something out of the blue, does not address any of my suggestions, and does not even try to explain why. |
skvoboo
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Commit has been updated. |
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Hrm. You could have left more work for me to analyze those data, but not much... |
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... and I just realized that you also kept the information to yourself that the |
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| if (INIT_PROC_ADDR(GetFinalPathNameByHandleW)) { | ||
| HANDLE hnd = CreateFileW(cwd, 0, | ||
| FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, |
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In the meantime I found reports that In all, I am much more reluctant about this change now. There just have been many unexpected issues with it which makes me expect more to come. And all of that for only an obscure use case where somebody works from within a directory whose parent directory they have no business listing. I prefer to have substantially less doubts about Pull Requests. Let's see whether you can dispel them. |
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Are your doubts dispelled? |
No. In fact, now I am even more doubtful, because I would have at least expected you to come up with a link to authoritative documentation that states clearly what one can expect on which Windows versions. Now I am more certain than before that you did not look whether it works on all Windows versions we try to support, you probably just tested this patch in your setup and did not care whether it works elsewhere, too. I have been bitten too often in the past by accepting patches in too good faith only to find out that I was left with fixing users' broken setups. There are two ways forward with this Pull Request:
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`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 of 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 <[email protected]>
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Commit has been updated. |
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Thank you, @skvoboo this commit was a real pleasure to read and indeed managed to reinstate my trust in it, in particular because it simply cannot cause regressions due to handling only the case when it would have failed earlier. |
Use GetFinalPathNameByHandleW instead of GetLongPathNameW to get full path
Pull request for issue #598