Subject: Re: [PATCH 8/8] Support "**" wildcard in .gitignore and .gitattributes

From: Michael Haggerty <[email-masked]>
Date: Tue, 09 Oct 2012 09:57:51 +0200

I like how this series is going and it's going to be a nice new feature.
 Some comments...

It would be helpful if you would use

    --subject-prefix='PATCH v3'

etc. to help spectators keep track of the different versions of your
patch series.

On 10/09/2012 05:09 AM, Nguyễn Thái Ngọc Duy wrote:
> 
> Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
> ---
>  Documentation/gitignore.txt        | 19 +++++++++++++++++++
>  attr.c                             |  4 +++-
>  dir.c                              |  4 +++-
>  t/t0003-attributes.sh              | 38 ++++++++++++++++++++++++++++++++++++++
>  t/t3001-ls-files-others-exclude.sh | 19 +++++++++++++++++++
>  5 files changed, 82 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/gitignore.txt b/Documentation/gitignore.txt
> index 96639e0..5a9c9f7 100644
> --- a/Documentation/gitignore.txt
> +++ b/Documentation/gitignore.txt
> @@ -104,6 +104,25 @@ PATTERN FORMAT
>     For example, "/{asterisk}.c" matches "cat-file.c" but not
>     "mozilla-sha1/sha1.c".
>  
> +Two consecutive asterisks ("`**`") in patterns matched against
> +full pathname may have special meaning:
> +
> + - A leading "`**`" followed by a slash means match in all
> +   directories. For example, "`**/foo`" matches file or directory
> +   "`foo`" anywhere, the same as pattern "`foo`". "**/foo/bar"
> +   matches file or directory "`bar`" anywhere that is directly
> +   under directory "`foo`".
> +
> + - A trailing "/**" matches everything inside. For example,
> +   "abc/**" is equivalent to "`/abc/`".

It seems odd that you add a leading slash in this example.  I assume
that is because of the rule that a pattern containing a slash is
considered anchored at the current directory.  But I find it confusing
because the addition of the leading slash is not part of the rule you
are trying to illustrate here, and is therefore a distraction.  I
suggest that you write either

- A trailing "/**" matches everything inside. For example,
  "/abc/**" is equivalent to "`/abc/`".

or

- A trailing "/**" matches everything inside. For example,
  "abc/**" is equivalent to "`abc/`" (which is also equivalent
  to "`/abc/`").

> +
> + - A slash followed by two consecutive asterisks then a slash
> +   matches zero or more directories. For example, "`a/**/b`"
> +   matches "`a/b`", "`a/x/b`", "`a/x/y/b`" and so on.
> +
> + - Consecutive asterisks otherwise are treated like normal
> +   asterisk wildcards.
> +

I don't like the last rule.  (1) This construct is superfluous; why
wouldn't the user just use a single asterisk?  (2) Allowing this
construct means that it could appear in .gitignore files, creating
unnecessary confusion: extrapolating from the other meanings of "**"
users would expect that it would somehow match slashes.  (3) It is
conceivable (though admittedly unlikely) that we might want to assign a
distinct meaning to this construct in the future, and accepting it now
as a different way to spell "*" would prevent such a change.

Perhaps this rule was intended for backwards compatibility?

I think it would be preferable to say that other uses of consecutive
asterisks are undefined, and probably make them trigger a warning.

>  NOTES
>  -----
>  
> diff --git a/attr.c b/attr.c
> index 887a9ae..e85e5ed 100644
> --- a/attr.c
> +++ b/attr.c
> @@ -12,6 +12,7 @@
>  #include "exec_cmd.h"
>  #include "attr.h"
>  #include "dir.h"
> +#include "wildmatch.h"
>  
>  const char git_attr__true[] = "(builtin)true";
>  const char git_attr__false[] = "\0(builtin)false";
> @@ -666,7 +667,8 @@ static int path_matches(const char *pathname, int pathlen,
>  		return 0;
>  	if (baselen != 0)
>  		baselen++;
> -	return fnmatch_icase(pattern, pathname + baselen, FNM_PATHNAME) == 0;
> +	return wildmatch(pattern, pathname + baselen,
> +			 ignore_case ? FNM_CASEFOLD : 0);
>  }
>  
>  static int macroexpand_one(int attr_nr, int rem);
> diff --git a/dir.c b/dir.c
> index 4868339..dc721c0 100644
> --- a/dir.c
> +++ b/dir.c
> @@ -8,6 +8,7 @@
>  #include "cache.h"
>  #include "dir.h"
>  #include "refs.h"
> +#include "wildmatch.h"
>  
>  struct path_simplify {
>  	int len;
> @@ -575,7 +576,8 @@ int excluded_from_list(const char *pathname,
>  			namelen -= prefix;
>  		}
>  
> -		if (!namelen || !fnmatch_icase(exclude, name, FNM_PATHNAME))
> +		if (!namelen ||
> +		    wildmatch(exclude, name, ignore_case ? FNM_CASEFOLD : 0))
>  			return to_exclude;
>  	}
>  	return -1; /* undecided */
> diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
> index febc45c..67a5694 100755
> --- a/t/t0003-attributes.sh
> +++ b/t/t0003-attributes.sh
> @@ -232,4 +232,42 @@ test_expect_success 'bare repository: test info/attributes' '
>  	attr_check subdir/a/i unspecified
>  '
>  
> +test_expect_success '"**" test' '
> +	cd .. &&
> +	echo "**/f foo=bar" >.gitattributes &&
> +	cat <<\EOF >expect &&
> +f: foo: bar
> +a/f: foo: bar
> +a/b/f: foo: bar
> +a/b/c/f: foo: bar
> +EOF
> +	git check-attr foo -- "f" >actual 2>err &&
> +	git check-attr foo -- "a/f" >>actual 2>>err &&
> +	git check-attr foo -- "a/b/f" >>actual 2>>err &&
> +	git check-attr foo -- "a/b/c/f" >>actual 2>>err &&
> +	test_cmp expect actual &&
> +	test_line_count = 0 err
> +'
> +
> +test_expect_success '"**" with no slashes test' '
> +	echo "a**f foo=bar" >.gitattributes &&
> +	git check-attr foo -- "f" >actual &&
> +	cat <<\EOF >expect &&
> +f: foo: unspecified
> +af: foo: bar
> +axf: foo: bar
> +a/f: foo: unspecified
> +a/b/f: foo: unspecified
> +a/b/c/f: foo: unspecified
> +EOF
> +	git check-attr foo -- "f" >actual 2>err &&
> +	git check-attr foo -- "af" >>actual 2>err &&
> +	git check-attr foo -- "axf" >>actual 2>err &&
> +	git check-attr foo -- "a/f" >>actual 2>>err &&
> +	git check-attr foo -- "a/b/f" >>actual 2>>err &&
> +	git check-attr foo -- "a/b/c/f" >>actual 2>>err &&
> +	test_cmp expect actual &&
> +	test_line_count = 0 err
> +'
> +
>  test_done
> diff --git a/t/t3001-ls-files-others-exclude.sh b/t/t3001-ls-files-others-exclude.sh
> index c8fe978..278315d 100755
> --- a/t/t3001-ls-files-others-exclude.sh
> +++ b/t/t3001-ls-files-others-exclude.sh
> @@ -214,4 +214,23 @@ test_expect_success 'subdirectory ignore (l1)' '
>  	test_cmp expect actual
>  '
>  
> +
> +test_expect_success 'ls-files with "**" patterns' '
> +	cat <<\EOF >expect &&
> +a.1
> +one/a.1
> +one/two/a.1
> +three/a.1
> +EOF
> +	git ls-files -o -i --exclude "**/a.1" >actual
> +	test_cmp expect actual
> +'
> +
> +
> +test_expect_success 'ls-files with "**" patterns and no slashes' '
> +	: >expect &&
> +	git ls-files -o -i --exclude "one**a.1" >actual &&
> +	test_cmp expect actual
> +'
> +
>  test_done
> 

Michael

-- 
Michael Haggerty
[email-masked]
http://softwareswirl.blogspot.com/