"git describe --exact-match X" is designed to fail when no tags are
pointing at X. When given "--no-exact-match", the command line
parser did the same thing as "--exact-match", which was clearly
bogus.
What "--no-exact-match" should do is not entirely clear, though.
Internally, there is an integer "max-candidates" that specifies how
many possible "describe" names are computed (among which, the best
name is picked), and this limit is set to 10 by default. The
"--candidates=<number>" option sets it to an arbitrary number (the
idea being that by spending a bit more computing resource, we might
be able to come up with a better name). "--exact-match" uses this
mechanism to express that the user refuses to accept a name that is
any non-zero distance away from a tag, and it does so by setting the
limit to 0.
Making "--no-exact-match" reset the counter to its default value
would allow "git describe --exact-match --no-exact-match X" to
defeat the earlier "--exact-match", and that is the solution we
adopt here in this patch. However, it is not clear what should
happen in this command:
git describe --exact-match --candidates=20 --no-exact-match X
Saying --candidates=20 allows us to go inexact, but then should
"--no-exact-match" become a no-op? The implementation in this patch
resets the counter to its default value, defeating the earlier
setting done by the "--candidates" option. We probably could solve
it by introducing an extra variable and combining the two after
parse_options() returns, but let's declare that it is not worth
solving and use the simpler solution, i.e. "--no-exact-match" resets
the limit to its default value.
The "--no-exact-match" option was not covered in the tests, so let's
add a few. Also add a case where --exact-match option is used on a
commit that cannot be described without distance from tags and make
sure the command fails.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
builtin/describe.c | 11 ++++++++---
t/t6120-describe.sh | 8 ++++++++
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/builtin/describe.c b/builtin/describe.c
index 55b4baaa22..879f8a8d45 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -34,13 +34,15 @@ static const char * const describe_usage[] = {
NULL
};
+#define DEFAULT_MAX_CANDIATES 10
+
static int debug; /* Display lots of verbose info */
static int all; /* Any valid ref can be used */
static int tags; /* Allow lightweight tags */
static int longformat;
static int first_parent;
static int abbrev = -1; /* unspecified */
-static int max_candidates = 10;
+static int max_candidates = DEFAULT_MAX_CANDIATES;
static struct hashmap names;
static int have_util;
static struct string_list patterns = STRING_LIST_INIT_NODUP;
@@ -567,8 +569,11 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
OPT_BOOL(0, "long", &longformat, N_("always use long format")),
OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
OPT__ABBREV(&abbrev),
- OPT_SET_INT(0, "exact-match", &max_candidates,
- N_("only output exact matches"), 0),
+ OPT_SET_INT_F(0, "exact-match", &max_candidates,
+ N_("only output exact matches"), 0, PARSE_OPT_NONEG),
+ OPT_SET_INT_F(0, "no-exact-match", &max_candidates,
+ N_("only output exact matches"), DEFAULT_MAX_CANDIATES,
+ PARSE_OPT_NONEG),
OPT_INTEGER(0, "candidates", &max_candidates,
N_("consider <n> most recent tags (default: 10)")),
OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index c9afcef201..0a5c487540 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -85,6 +85,7 @@ check_describe e-1-gHASH --tags HEAD^^
check_describe c-2-gHASH --tags HEAD^^2
check_describe B --tags HEAD^^2^
check_describe e --tags HEAD^^^
+check_describe e --tags --exact-match HEAD^^^
check_describe heads/main --all HEAD
check_describe tags/c-6-gHASH --all HEAD^
@@ -96,6 +97,13 @@ check_describe A-3-gHASH --long HEAD^^2
check_describe c-7-gHASH --tags
check_describe e-3-gHASH --first-parent --tags
+check_describe c-7-gHASH --tags --no-exact-match HEAD
+check_describe e-3-gHASH --first-parent --tags --no-exact-match HEAD
+
+test_expect_success '--exact-match failure' '
+ test_must_fail git describe --exact-match HEAD 2>err
+'
+
test_expect_success 'describe --contains defaults to HEAD without commit-ish' '
echo "A^0" >expect &&
git checkout A &&
--
2.41.0-376-gcba07a324d
