describe: fix --contains when a tag is given as input

"git describe" takes a commit and gives it a name based on tags in
its neighbourhood.  The command does take a commit-ish but when
given a tag that points at a commit, it should dereference the tag
before computing the name for the commit.

As the whole processing is internally delegated to name-rev, if we
unwrap tags down to the underlying commit when invoking name-rev, it
will make the name-rev issue an error message based on the unwrapped
object name (i.e. either 40-hex object name, or "$tag^0") that is
different from what the end-user gave to the command when the commit
cannot be described.  Introduce an internal option --peel-tag to the
name-rev to tell it to unwrap a tag in its input from the command
line.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/describe.c b/builtin/describe.c
index db41cd7974698aeb70b91d48a36b09ce2e558ef1..7d73722f59b10b5fe302498bb83c9ab3313b89b0 100644 (file)
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -446,7 +446,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
                struct argv_array args;
 
                argv_array_init(&args);
-               argv_array_pushl(&args, "name-rev", "--name-only", "--no-undefined",
+               argv_array_pushl(&args, "name-rev",
+                                "--peel-tag", "--name-only", "--no-undefined",
                                 NULL);
                if (always)
                        argv_array_push(&args, "--always");

diff --git a/builtin/name-rev.c b/builtin/name-rev.c
index 4c7cc62a9ca9320a5582e824b0c811bece1c7610..0aaa19e4abeb462b2f1d05d5e03aa29bee810db8 100644 (file)
--- a/builtin/name-rev.c
+++ b/builtin/name-rev.c
@@ -307,7 +307,7 @@ static void name_rev_line(char *p, struct name_ref_data *data)
 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 {
        struct object_array revs = OBJECT_ARRAY_INIT;
-       int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0;
+       int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
        struct name_ref_data data = { 0, 0, NULL };
        struct option opts[] = {
                OPT_BOOLEAN(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
@@ -320,6 +320,12 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
                OPT_BOOLEAN(0, "undefined", &allow_undefined, N_("allow to print `undefined` names")),
                OPT_BOOLEAN(0, "always",     &always,
                           N_("show abbreviated commit object as fallback")),
+               {
+                       /* A Hidden OPT_BOOL */
+                       OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
+                       N_("dereference tags in the input (internal use)"),
+                       PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
+               },
                OPT_END(),
        };
 
@@ -361,6 +367,15 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
                        if (cutoff > commit->date)
                                cutoff = commit->date;
                }
+
+               if (peel_tag) {
+                       if (!commit) {
+                               fprintf(stderr, "Could not get commit for %s. Skipping.\n",
+                                       *argv);
+                               continue;
+                       }
+                       object = (struct object *)commit;
+               }
                add_object_array(object, *argv, &revs);
        }
 

diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 1d20854609e8f752b446d6657fcbec479220f937..c0e5b2a6275df2d92172327b2d629cc73720423e 100755 (executable)
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -186,4 +186,16 @@ test_expect_success 'name-rev with exact tags' '
        test_cmp expect actual
 '
 
+test_expect_success 'describe --contains with the exact tags' '
+       echo "A^0" >expect &&
+       tag_object=$(git rev-parse refs/tags/A) &&
+       git describe --contains $tag_object >actual &&
+       test_cmp expect actual &&
+
+       echo "A^0" >expect &&
+       tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+       git describe --contains $tagged_commit >actual &&
+       test_cmp expect actual
+'
+
 test_done