Re: [PATCH v7 04/17] ref-filter: modify "%(objectname:short)" to take length

Add tests and documentation for the same.

Mentored-by: Christian Couder [off-list ref]
Mentored-by: Matthieu Moy [off-list ref]
Helped-by: Jacob Keller [off-list ref]
Signed-off-by: Karthik Nayak <redacted>
---
 Documentation/git-for-each-ref.txt |  4 ++++
 ref-filter.c                       | 25 +++++++++++++++++++------
 t/t6300-for-each-ref.sh            | 10 ++++++++++
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index b7b8560..92184c4 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt

@@ -107,6 +107,10 @@ objectsize::
 objectname::
        The object name (aka SHA-1).
        For a non-ambiguous abbreviation of the object name append `:short`.
+       For an abbreviation of the object name with desired length append
+       `:short=<length>`, where the minimum length is MINIMUM_ABBREV. The
+       length may be exceeded to ensure unique object names.
+

 upstream::
        The name of a local ref which can be considered ``upstream''

diff --git a/ref-filter.c b/ref-filter.c
index 44481c3..fe4ea2b 100644
--- a/ref-filter.c
+++ b/ref-filter.c

@@ -55,7 +55,10 @@ static struct used_atom {
                        const char *if_equals,
                                *not_equals;
                } if_then_else;
-               enum { O_FULL, O_SHORT } objectname;
+               struct {
+                       enum { O_FULL, O_LENGTH, O_SHORT } option;
+                       unsigned int length;
+               } objectname;
        } u;
 } *used_atom;
 static int used_atom_cnt, need_tagged, need_symref;

@@ -118,10 +121,17 @@ static void contents_atom_parser(struct used_atom *atom, const char *arg)
 static void objectname_atom_parser(struct used_atom *atom, const char *arg)
 {
        if (!arg)
-               atom->u.objectname = O_FULL;
+               atom->u.objectname.option = O_FULL;
        else if (!strcmp(arg, "short"))
-               atom->u.objectname = O_SHORT;
-       else
+               atom->u.objectname.option = O_SHORT;
+       else if (skip_prefix(arg, "short=", &arg)) {
+               atom->u.objectname.option = O_LENGTH;
+               if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
+                   atom->u.objectname.length == 0)
+                       die(_("positive value expected objectname:short=%s"), arg);
+               if (atom->u.objectname.length < MINIMUM_ABBREV)
+                       atom->u.objectname.length = MINIMUM_ABBREV;

+       } else
                die(_("unrecognized %%(objectname) argument: %s"), arg);
 }

@@ -591,12 +601,15 @@ static int grab_objectname(const char *name, const unsigned char *sha1,
                           struct atom_value *v, struct used_atom *atom)
 {
        if (starts_with(name, "objectname")) {
-               if (atom->u.objectname == O_SHORT) {
+               if (atom->u.objectname.option == O_SHORT) {
                        v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
                        return 1;

-               } else if (atom->u.objectname == O_FULL) {
+               } else if (atom->u.objectname.option == O_FULL) {
                        v->s = xstrdup(sha1_to_hex(sha1));
                        return 1;
+               } else if (atom->u.objectname.option == O_LENGTH) {
+                       v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
+                       return 1;
                } else
                        die("BUG: unknown %%(objectname) option");
        }

diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 19a2823..2be0a3f 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh

@@ -60,6 +60,8 @@ test_atom head objecttype commit
 test_atom head objectsize 171
 test_atom head objectname $(git rev-parse refs/heads/master)
 test_atom head objectname:short $(git rev-parse --short refs/heads/master)
+test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
+test_atom head objectname:short=10 $(git rev-parse --short=10 refs/heads/master)
 test_atom head tree $(git rev-parse refs/heads/master^{tree})
 test_atom head parent ''
 test_atom head numparent 0

@@ -99,6 +101,8 @@ test_atom tag objecttype tag
 test_atom tag objectsize 154
 test_atom tag objectname $(git rev-parse refs/tags/testtag)
 test_atom tag objectname:short $(git rev-parse --short refs/tags/testtag)
+test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
+test_atom head objectname:short=10 $(git rev-parse --short=10 refs/heads/master)
 test_atom tag tree ''
 test_atom tag parent ''
 test_atom tag numparent ''

@@ -164,6 +168,12 @@ test_expect_success 'Check invalid format specifiers are errors' '
        test_must_fail git for-each-ref --format="%(authordate:INVALID)" refs/heads
 '

+test_expect_success 'arguments to %(objectname:short=) must be positive integers' '
+       test_must_fail git for-each-ref --format="%(objectname:short=0)" &&
+       test_must_fail git for-each-ref --format="%(objectname:short=-1)" &&
+       test_must_fail git for-each-ref --format="%(objectname:short=foo)"
+'
+
 test_date () {
        f=$1 &&
        committer_date=$2 &&
--

2.10.2