Re: [PATCH] Fix crlf attribute handling to match documentation

Andy Parkins [off-list ref] writes:

gitattributes.txt says, of the crlf attribute:

 Set::
    Setting the `crlf` attribute on a path is meant to mark
    the path as a "text" file.  'core.autocrlf' conversion
    takes place without guessing the content type by
    inspection.

That is to say that the crlf attribute does not force the file to have
CRLF line endings, instead it removes the autocrlf guesswork and forces
the file to be treated as text.  Then, whatever line ending is defined
by the autocrlf setting is applied.

Thanks; I looked at the patch (although I am still _physically_
at work ;-).  I think your code is correct but the explanation
is slightly misleading.

However, that is not what convert.c was doing.  The conversion to CRLF
was being skipped in crlf_to_worktree() when the following condition was
true:

 action == CRLF_GUESS && auto_crlf <= 0

The check you modified in the first hunk is not the above '<='
comparison but is this:

	(action == CRLF_GUESS && !auto_crlf)

and "core.autocrlf = input" makes "auto_crlf = -1", so when
action is not GUESS, or even when action is GUESS, if the config
is set to "input", the if() statement you patched in the first
hunk should not trigger.  The above description is different from
what the code was doing.

The logic (in crlf_to_git, which is the input codepath) should be:

	* if action is BINARY, do nothing (obviously -- and the
          code gets this right).

	* if action is GUESS, do nothing if config says false
          (we want 'input' and 'true' to apply the munging after
          guessing).

	* if action is TEXT or INPUT, do not guess but do CRLF
          only on platforms that need it -- which means where
          auto_crlf is -1 (input) or 1 (true).  Otherwise do not
          do the conversion.

The original code gets the third case incorrectly, and your
patch fixes it by returning early in that case as well.

The output codepath is the same.  Regardless of action
(GUESS/TEXT/INPUT), we will not do anything if config says 'false'
or 'input', so removing the check with "action == GUESS" is the
right thing.

On Saturday 2007, May 19, Junio C Hamano wrote:

The check you modified in the first hunk is not the above '<='
comparison but is this:

I was talking about the second hunk there though, which I mentioned 
with "...skipped in crlf_to_worktree()...".   In which case the 
description matches.

	(action == CRLF_GUESS && !auto_crlf)

and "core.autocrlf = input" makes "auto_crlf = -1", so when
action is not GUESS, or even when action is GUESS, if the config
is set to "input", the if() statement you patched in the first
hunk should not trigger.  The above description is different from
what the code was doing.

As I say, the description was for the second hunk.

The fault was my last paragraph, "Similarly for crlf_to_worktree(), if 
core.autocrlf is false, no", which should have said "Similarly for 
crlf_to_git()".  Sorry.

With that small change I think my description was correct.  However, it 
obviously wasn't clear - apologies.



Andy

-- 
Dr Andy Parkins, M Eng (hons), MIET
andyparkins@gmail.com