Junio C HamanoWhen matching a non-wildcard LHS of a refspec against a list of refs, find_ref_by_name_abbrev() returns the first ref that matches using any DWIM rules used by refname_match() in refs.c, even if a better match occurs later in the list of refs.
This causes unexpected behavior when (for example) fetching using the refspec "refs/heads/s:<something>" from a remote with both "refs/heads/refs/heads/s" and "refs/heads/s"; even if the former was inadvertently created, one would still expect the latter to be fetched. Similarly, when both a tag T and a branch T exist, fetching T should favor the tag, just like how local refname disambiguation rule works. But because the code walks over ls-remote output from the remote, which happens to be sorted in alphabetical order and has refs/heads/T before refs/tags/T, a request to fetch T is (mis)interpreted as fetching refs/heads/T.
Update refname_match(), all of whose current callers care only if it returns non-zero (i.e. matches) to see if an abbreviated name can mean the full name being tested, so that it returns a positive integer whose magnitude can be used to tell the precedence, and fix the find_ref_by_name_abbrev() function not to stop at the first match but find the match with the highest precedence.
This is based on an earlier work, which special cased only the exact matches, by Jonathan Tan.
Signed-off-by: Junio C Hamano <gitster@pobox.com> ---
* This time, with a log message, updated "precedence" number, a bit of in-code comment and a new test to show that the fix extends to non-exact disambiguation as well.
refs.c | 16 +++++++++++----- remote.c | 13 ++++++++++--- t/t5510-fetch.sh | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 56 insertions(+), 8 deletions(-)
Show changes to 3 files +56 −8
refs.c, remote.c, t/t5510-fetch.sh
diff --git a/refs.c b/refs.c index 20ba82b434..d1be61b1b5 100644 --- a/refs.c +++ b/refs.c @@ -487,16 +487,22 @@ static const char *ref_rev_parse_rules[] = { NULL }; +/* + * Is it possible that the caller meant full_name with abbrev_name? + * If so return a non-zero value to signal "yes"; the magnitude of + * the returned value gives the precedence used for disambiguation. + * + * If abbrev_name cannot mean full_name, return 0. + */ int refname_match(const char *abbrev_name, const char *full_name) { const char **p; const int abbrev_name_len = strlen(abbrev_name); + const int num_rules = ARRAY_SIZE(ref_rev_parse_rules) - 1; - for (p = ref_rev_parse_rules; *p; p++) { - if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) { - return 1; - } - } + for (p = ref_rev_parse_rules; *p; p++) + if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) + return &ref_rev_parse_rules[num_rules] - p; return 0; } diff --git a/remote.c b/remote.c index c10d87c246..4a3e7ba136 100644 --- a/remote.c +++ b/remote.c @@ -1880,11 +1880,18 @@ static struct ref *get_expanded_map(const struct ref *remote_refs, static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name) { const struct ref *ref; + const struct ref *best_match = NULL; + int best_score = 0; + for (ref = refs; ref; ref = ref->next) { - if (refname_match(name, ref->name)) - return ref; + int score = refname_match(name, ref->name); + + if (best_score < score) { + best_match = ref; + best_score = score; + } } - return NULL; + return best_match; } struct ref *get_remote_ref(const struct ref *remote_refs, const char *name) diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh index da9ac00557..858381a788 100755 --- a/t/t5510-fetch.sh +++ b/t/t5510-fetch.sh @@ -535,6 +535,41 @@ test_expect_success "should be able to fetch with duplicate refspecs" ' ) ' +test_expect_success 'LHS of refspec follows ref disambiguation rules' ' + mkdir lhs-ambiguous && + ( + cd lhs-ambiguous && + git init server && + test_commit -C server unwanted && + test_commit -C server wanted && + + git init client && + + # Check a name coming after "refs" alphabetically ... + git -C server update-ref refs/heads/s wanted && + git -C server update-ref refs/heads/refs/heads/s unwanted && + git -C client fetch ../server +refs/heads/s:refs/heads/checkthis && + git -C server rev-parse wanted >expect && + git -C client rev-parse checkthis >actual && + test_cmp expect actual && + + # ... and one before. + git -C server update-ref refs/heads/q wanted && + git -C server update-ref refs/heads/refs/heads/q unwanted && + git -C client fetch ../server +refs/heads/q:refs/heads/checkthis && + git -C server rev-parse wanted >expect && + git -C client rev-parse checkthis >actual && + test_cmp expect actual && + + # Tags are preferred over branches like refs/{heads,tags}/* + git -C server update-ref refs/tags/t wanted && + git -C server update-ref refs/heads/t unwanted && + git -C client fetch ../server +t:refs/heads/checkthis && + git -C server rev-parse wanted >expect && + git -C client rev-parse checkthis >actual + ) +' + # configured prune tests set_config_tristate () {
-- 2.18.0-321-gffc6fa0e39
