Re: [msysGit] [PATCH/RFC] autocrlf: Make it work also for un-normalized repositories

> Previously, autocrlf would only work well for normalized
> repositories. Any text files that contained CRLF in the repository
> would cause problems, and would be modified when handled with
> core.autocrlf set.
> 
> Change autocrlf to not do any conversions to files that in the
> repository already contain a CR. git with autocrlf set will never
> create such a file, or change a LF only file to contain CRs, so the
> (new) assumption is that if a file contains a CR, it is intentional,
> and autocrlf should not change that.
> 
> The following sequence should now always be a NOP even with autocrlf
> set (assuming a clean working directory):
> 
> git checkout <something>
> touch *
> git add -A .    (will add nothing)
> git comit       (nothing to commit)

> Previously this would break for any text file containing a CR
> 
> Signed-off-by: Finn Arne Gangstad <finag@pvv.org>
> ---
> 
> Some of you may have been folowing Eyvind's excellent thread about
> trying to make end-of-line translation in git a bit smoother.
> 
> I decided to attack the problem from a different angle: Is it possible
> to make autocrlf behave non-destructively for all the previous problem cases?
> 
> Stealing the problem from Eyvind's initial mail (paraphrased and
> summarized a bit):
> 
> 1. Setting autocrlf globally is a pain since autocrlf does not work well
>    with CRLF in the repo
> 2. Setting it in individual repos is hard since you do it "too late"
>    (the clone will get it wrong)
> 3. If someone checks in a file with CRLF later, you get into problems again
> 4. If a repository once has contained CRLF, you can't tell autocrlf
>    at which commit everything is sane again
> 5. autocrlf does needless work if you know that all your users want
>    the same EOL style.
> 
> I belive that this patch makes autocrlf a safe (and good) default
> setting for Windows, and this solves problems 1-4.
> 
> I implemented it by looking for CR charactes in the index, and
> aborting any conversion attempt if this is found. The code to read
> the index contents was copied pretty verbatim from attr.c, and should
> probably be made into a non-static function instead if there is no
> better way of doing this.

> diff --git a/convert.c b/convert.c
> index 4f8fcb7..9d062c8 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -120,6 +120,43 @@ static void check_safe_crlf(const char *path, int action,
>  	}
>  }
>  
> +static int has_cr_in_index(const char *path)
> +{
> +	int pos, len;
> +	unsigned long sz;
> +	enum object_type type;
> +	void *data;
> +	int has_cr;
> +	struct index_state *istate = &the_index;
> +
> +	len = strlen(path);
> +	pos = index_name_pos(istate, path, len);
> +	if (pos < 0) {
> +		/*
> +		 * We might be in the middle of a merge, in which
> +		 * case we would read stage #2 (ours).
> +		 */
> +		int i;
> +		for (i = -pos - 1;
> +		     (pos < 0 && i < istate->cache_nr &&
> +		      !strcmp(istate->cache[i]->name, path));
> +		     i++)
> +			if (ce_stage(istate->cache[i]) == 2)
> +				pos = i;
> +	}