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Re: [PATCH] Check for existence of the path before processing '..'
- From: Christopher Faylor <cgf-use-the-mailinglist-please at cygwin dot com>
- To: cygwin at cygwin dot com
- Date: Tue, 11 Jun 2013 10:20:02 -0400
- Subject: Re: [PATCH] Check for existence of the path before processing '..'
- References: <001401ce66a4$bb9029a0$32b07ce0$%fedin at samsung dot com>
- Reply-to: cygwin at cygwin dot com
On Tue, Jun 11, 2013 at 05:08:13PM +0400, Fedin Pavel wrote:
> Some time ago i reported ability to access things like
>"/usr/nonexistent/..bin". I still had this problem and i tried my hands on
> The patch works by checking the actual existence of the path before
>removing the last component from it. For performance reasons, only one check
>is done for things like "../..". Because, obviously, if "/foo/bar/baz"
>exists, then "/foo/bar" exists too. Also, the check is done only after some
>components have been added to the path. So, for example, current directory
>(obtained when processing relative paths), will not be checked.
> I tried to add a similar test also to normalize_win32_path() function,
>however this broke things like "cd /usr/src/..". For some reason, a POSIX
>version of the path (but with reversed slashes) is passed to this routine
>when expanding mount points, so, consequently, test for "\usr\src" using
> I think it's ok, at least POSIX paths now behave in POSIX way. I have
>tested against performance, there is some loss (~0.2 seconds), but only for
> With this patch i am able to compile the latest version of glibc with no
You introduce a check_parent flag which is set every time a non-slash
character is found. That doesn't seem right. It seems like it should
be set whenever you see a slash.
Also you are calling path_conv recursively. I assume that is where you
are seeing a performance hit.
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