Re: [PATCH 2/2] tag: do not show ambiguous tag names as "tags/foo"

> Since b7cc53e9 (tag.c: use 'ref-filter' APIs, 2015-07-11),
> git-tag has started showing tags with ambiguous names (i.e.,
> when both "heads/foo" and "tags/foo" exists) as "tags/foo"
> instead of just "foo". This is both:
>
>   - pointless; the output of "git tag" includes only
>     refs/tags, so we know that "foo" means the one in
>     "refs/tags".
>
> and
>
>   - ambiguous; in the original output, we know that the line
>     "foo" means that "refs/tags/foo" exists. In the new
>     output, it is unclear whether we mean "refs/tags/foo" or
>     "refs/tags/tags/foo".
>
> The reason this happens is that commit b7cc53e9 switched
> git-tag to use ref-filter's "%(refname:short)" output
> formatting, which was adapted from for-each-ref.
> ...

>  Documentation/git-for-each-ref.txt |  6 +++++-
>  Documentation/git-tag.txt          |  2 +-
>  builtin/tag.c                      |  4 ++--
>  ref-filter.c                       | 13 ++++++++++++-
>  t/t3203-branch-output.sh           |  8 ++++++++
>  t/t6300-for-each-ref.sh            |  4 ++++
>  t/t7004-tag.sh                     |  8 ++++++++
>  7 files changed, 40 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
> index 06208c4..f15c817 100644
> --- a/Documentation/git-for-each-ref.txt
> +++ b/Documentation/git-for-each-ref.txt
> @@ -92,7 +92,11 @@ refname::
>  	The name of the ref (the part after $GIT_DIR/).
>  	For a non-ambiguous short name of the ref append `:short`.
>  	The option core.warnAmbiguousRefs is used to select the strict
> -	abbreviation mode.
> +	abbreviation mode. If `strip=<N>` is appended, strips `<N>`
> +	slash-separated path components from the front of the refname
> +	(e.g., `%(refname:strip=2)` turns `refs/tags/foo` into `foo`.
> +	If the ref has fewer components than `<N>`, the whole,
> +	unstripped `%(refname)` is printed.
>  
>  objecttype::
>  	The type of the object (`blob`, `tree`, `commit`, `tag`).
> diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
> index 7220e5e..abab481 100644
> --- a/Documentation/git-tag.txt
> +++ b/Documentation/git-tag.txt
> @@ -163,7 +163,7 @@ This option is only applicable when listing tags without annotation lines.
>  	A string that interpolates `%(fieldname)` from the object
>  	pointed at by a ref being shown.  The format is the same as
>  	that of linkgit:git-for-each-ref[1].  When unspecified,
> -	defaults to `%(refname:short)`.
> +	defaults to `%(refname:strip=2)`.
>  
>  --[no-]merged [<commit>]::
>  	Only list tags whose tips are reachable, or not reachable
> diff --git a/builtin/tag.c b/builtin/tag.c
> index 8db8c87..1705c94 100644
> --- a/builtin/tag.c
> +++ b/builtin/tag.c
> @@ -44,11 +44,11 @@ static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting, con
>  	if (!format) {
>  		if (filter->lines) {
>  			to_free = xstrfmt("%s %%(contents:lines=%d)",
> -					  "%(align:15)%(refname:short)%(end)",
> +					  "%(align:15)%(refname:strip=2)%(end)",
>  					  filter->lines);
>  			format = to_free;
>  		} else
> -			format = "%(refname:short)";
> +			format = "%(refname:strip=2)";
>  	}
>  
>  	verify_ref_format(format);
> diff --git a/ref-filter.c b/ref-filter.c
> index 7bef7f8..9f54adc 100644
> --- a/ref-filter.c
> +++ b/ref-filter.c
> @@ -909,12 +909,23 @@ static void populate_value(struct ref_array_item *ref)
>  		formatp = strchr(name, ':');
>  		if (formatp) {
>  			int num_ours, num_theirs;
> +			const char *arg;
>  
>  			formatp++;
>  			if (!strcmp(formatp, "short"))
>  				refname = shorten_unambiguous_ref(refname,
>  						      warn_ambiguous_refs);
> -			else if (!strcmp(formatp, "track") &&
> +			else if (skip_prefix(formatp, "strip=", &arg)) {
> +				int strip = atoi(arg);
> +				const char *start = refname;
> +				while (strip && *start) {
> +					if (*start == '/')
> +						strip--;
> +					start++;
> +				}
> +				if (!strip)
> +					refname = start;
> +			} else if (!strcmp(formatp, "track") &&
>  				 (starts_with(name, "upstream") ||
>  				  starts_with(name, "push"))) {
>  
> diff --git a/t/t3203-branch-output.sh b/t/t3203-branch-output.sh
> index d3913f9..4261403 100755
> --- a/t/t3203-branch-output.sh
> +++ b/t/t3203-branch-output.sh
> @@ -176,4 +176,12 @@ test_expect_success 'git branch --points-at option' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'ambiguous branch/tag not marked' '
> +	git tag ambiguous &&
> +	git branch ambiguous &&
> +	echo "  ambiguous" >expect &&
> +	git branch --list ambiguous >actual &&
> +	test_cmp expect actual
> +'
> +
>  test_done
> diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
> index 859b237..1f3abeb 100755
> --- a/t/t6300-for-each-ref.sh
> +++ b/t/t6300-for-each-ref.sh
> @@ -50,6 +50,10 @@ test_atom() {
>  
>  test_atom head refname refs/heads/master
>  test_atom head refname:short master
> +test_atom head refname:strip=0 refs/heads/master
> +test_atom head refname:strip=1 heads/master
> +test_atom head refname:strip=2 master
> +test_atom head refname:strip=3 refs/heads/master
>  test_atom head upstream refs/remotes/origin/master
>  test_atom head upstream:short origin/master
>  test_atom head push refs/remotes/myfork/master
> diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
> index 2797f22..cf3469b 100755
> --- a/t/t7004-tag.sh
> +++ b/t/t7004-tag.sh
> @@ -1558,4 +1558,12 @@ test_expect_success '--no-merged show unmerged tags' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'ambiguous branch/tags not marked' '
> +	git tag ambiguous &&
> +	git branch ambiguous &&
> +	echo ambiguous >expect &&
> +	git tag -l ambiguous >actual &&
> +	test_cmp expect actual
> +'
> +
>  test_done