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Re: [PATCH v2 03/17] safe_create_leading_directories(): add explicit "slash" pointer

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Jan 7, 2014, 09:26 UTC
Message-ID
<52CBC854.2060602@alum.mit.edu>
In-Reply-To
<xmqqppo5hsf9.fsf@gitster.dls.corp.google.com>
On 01/06/2014 07:32 PM, Junio C Hamano wrote:
Show 31 quoted lines
> Michael Haggerty <mhagger@alum.mit.edu> writes:
> 
>> Keep track of the position of the slash character independently of
>> "pos", thereby making the purpose of each variable clearer and
>> working towards other upcoming changes.
>>
>> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
>> ---
> 
> This step has an interaction with $gmane/239878 where Windows folks
> want it to pay attention to is_dir_sep()---over there, a backslash
> could separate directory path components.
> 
> AFAIK, the function was meant to be used only on paths we internally
> generate, and the paths we internally generate all are slash
> separated, so it could be argued that feeding a path, whose path
> components are separated by backslashes, that we obtained from the
> end user without converting it to the internal form in some
> codepaths (e.g. "$there" in "git clone $url $there") are bugs we
> acquired over time that need to be fixed, but it is easy enough to
> use is_dir_sep() here to work it around, and doing so will
> not negatively affect
> 
>  1. UNIX-only projects by forbidding use of a byte with backslash in
>     it as a path component character (yes, I am imagining using
>     Shift-JIS that can use a backslash as the second byte of
>     two-byte character in the pathname on UNIX); and
> 
>  2. UNIX-and-Windows mixed projects, as you cannot sanely use such a
>     pathname with backslash as part of a path component if its tree
>     needs to be checked out on Windows.

I agree that it would be reasonable to use is_dir_sep() in the implementation of this function, at least unless/until somebody does the work to figure out whether callers should really only be passing it forward-slash-normalized paths.

Please be careful, though, because I don't think this function is capable of handling arbitrary Windows paths, like for example //host/path format, either before or after my change.

Let me know if you would like me to merge or rebase the is_dir_sep() changes into this patch series.

Michael
-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/
Previous: Junio C HamanoNext: Junio C Hamano
Message 6 of 29 in “Fix some mkdir/rmdir races”
  1. 00/17 Fix some mkdir/rmdir racesMichael Haggerty, Jan 6, 2014
  2. 01/17 safe_create_leading_directories(): fix format of "if" chainingMichael Haggerty, Jan 6, 2014
  3. 02/17 safe_create_leading_directories(): reduce scope of local variableMichael Haggerty, Jan 6, 2014
  4. 03/17 safe_create_leading_directories(): add explicit "slash" pointerMichael Haggerty, Jan 6, 2014
  5. Junio C HamanoJan 6, 2014
  6. Michael HaggertyJan 7, 2014
  7. Junio C HamanoJan 7, 2014
  8. Sebastian SchuberthJan 19, 2014
  9. 04/17 safe_create_leading_directories(): rename local variableMichael Haggerty, Jan 6, 2014
  10. 05/17 safe_create_leading_directories(): split on first of multiple slashesMichael Haggerty, Jan 6, 2014
  11. 06/17 safe_create_leading_directories(): always restore slash at end of loopMichael Haggerty, Jan 6, 2014
  12. 07/17 safe_create_leading_directories(): introduce enum for return valuesMichael Haggerty, Jan 6, 2014
  13. 08/17 cmd_init_db(): when creating directories, handle errors conservativelyMichael Haggerty, Jan 6, 2014
  14. 09/17 safe_create_leading_directories(): add new error value SCLD_VANISHEDMichael Haggerty, Jan 6, 2014
  15. 10/17 lock_ref_sha1_basic(): on SCLD_VANISHED, retryMichael Haggerty, Jan 6, 2014
  16. Junio C HamanoJan 6, 2014
  17. Michael HaggertyJan 7, 2014
  18. 11/17 lock_ref_sha1_basic(): if locking fails with ENOENT, retryMichael Haggerty, Jan 6, 2014
  19. 12/17 remove_dir_recurse(): tighten condition for removing unreadable dirMichael Haggerty, Jan 6, 2014
  20. 13/17 remove_dir_recurse(): handle disappearing files and directoriesMichael Haggerty, Jan 6, 2014
  21. Junio C HamanoJan 6, 2014
  22. Michael HaggertyJan 7, 2014
  23. Junio C HamanoJan 7, 2014
  24. 14/17 rename_ref(): extract function rename_tmp_log()Michael Haggerty, Jan 6, 2014
  25. 15/17 rename_tmp_log(): handle a possible mkdir/rmdir raceMichael Haggerty, Jan 6, 2014
  26. 16/17 rename_tmp_log(): limit the number of remote_empty_directories() attemptsMichael Haggerty, Jan 6, 2014
  27. 17/17 rename_tmp_log(): on SCLD_VANISHED, retryMichael Haggerty, Jan 6, 2014
  28. Junio C HamanoJan 6, 2014
  29. Michael HaggertyJan 7, 2014

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