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bug#10733: 24.0.93; w32 file truncation
From: |
Ota, Takaaki |
Subject: |
bug#10733: 24.0.93; w32 file truncation |
Date: |
Mon, 6 Feb 2012 15:43:27 -0800 |
Don't you need to dispose fh properly?
-Tak
Mon, 6 Feb 2012 15:27:07 -0800: Óscar Fuentes <ofv@wanadoo.es> wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
>
> [snip]
>
> > No. The `stat' Emacs uses is in w32.c. What you see on
> > lib-src/ntlib.c is just a minimal subset of what we have in w32.c.
>
> That's important. Thanks.
>
> >> Symlinks are detected and handled specially on MSVCRT's stat. In
> >> aessence, for symlinks it uses fstat.
> >
> > But fstat probably calls GetFileInformationByHandle under the hood,
> > and we already call that function in w32.c:stat. So maybe the fix is
> > not as ugly and inelegant as you thought.
>
> Yup. This patch fixes the problem:
>
> diff --git a/src/w32.c b/src/w32.c
> index f610a36..035e1f2 100644
> --- a/src/w32.c
> +++ b/src/w32.c
> @@ -3444,6 +3444,29 @@ stat (const char * path, struct stat * buf)
> }
> }
>
> + buf->st_size = 0;
> +
> + if ((wfd.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) &&
> + (wfd.dwReserved0 == IO_REPARSE_TAG_SYMLINK))
> + {
> + HANDLE fh;
> + BY_HANDLE_FILE_INFORMATION info;
> +
> + if ((fh = CreateFile (name, 0, 0, NULL, OPEN_EXISTING,
> + FILE_FLAG_BACKUP_SEMANTICS, NULL))
> + && GetFileInformationByHandle (fh, &info))
> + {
> + buf->st_size = info.nFileSizeHigh;
> + buf->st_size <<= 32;
> + buf->st_size += info.nFileSizeLow;
> + }
> + else
> + {
> + errno = ENOENT;
> + return -1;
> + }
> + }
> +
> if (!(NILP (Vw32_get_true_file_attributes)
> || (EQ (Vw32_get_true_file_attributes, Qlocal) && is_slow_fs (name)))
> /* No access rights required to get info. */
> @@ -3532,9 +3555,12 @@ stat (const char * path, struct stat * buf)
> buf->st_dev = volume_info.serialnum;
> buf->st_rdev = volume_info.serialnum;
>
> - buf->st_size = wfd.nFileSizeHigh;
> - buf->st_size <<= 32;
> - buf->st_size += wfd.nFileSizeLow;
> + if (! buf->st_size)
> + {
> + buf->st_size = wfd.nFileSizeHigh;
> + buf->st_size <<= 32;
> + buf->st_size += wfd.nFileSizeLow;
> + }
>
> /* Convert timestamps to Unix format. */
> buf->st_mtime = convert_time (wfd.ftLastWriteTime);
>
>
> Maybe it can be integrated in the
>
> if (!(NILP(Vw32_get_true_file_attributes) ...
>
> hence reusing the calls to CreateFile and GetFileInformationByHandle and
> shortening the patch, but as I don't know what
> Vw32_get_true_file_attributes does, preferread to follow the safe way.
>
> However, we still have another implementation on ntlib.c.
>
> And the fix is just for the size. Don't know if there are other
> attributes suffer from the same problem. Possibly the right thing is to
> do what MSVCRT does:
>
> if is-symlink?
> use fstat
> fi
>
- bug#10733: 24.0.93; w32 file truncation, (continued)
- bug#10733: 24.0.93; w32 file truncation, Ota, Takaaki, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Lennart Borgman, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Lennart Borgman, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Lennart Borgman, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Lars Ingebrigtsen, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Óscar Fuentes, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation,
Ota, Takaaki <=
- bug#10733: 24.0.93; w32 file truncation, Óscar Fuentes, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/06
- bug#10733: 24.0.93; w32 file truncation, Óscar Fuentes, 2012/02/07
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/07
- bug#10733: 24.0.93; w32 file truncation, Eli Zaretskii, 2012/02/06
bug#10733: 24.0.93; w32 file truncation, Óscar Fuentes, 2012/02/05