Hi,
Junio C Hamano wrote:
> When 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.
Nicely explained.
[...]
> --- 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;
This is assuming ref_rev_parse_rules consists exactly of its items
followed by a NULL terminator, which is potentially a bit subtle. I
wonder if we should put
static const char *ref_rev_parse_rules[] = {
"%.*s",
"refs/%.*s",
"refs/tags/%.*s",
"refs/heads/%.*s",
"refs/remotes/%.*s",
"refs/remotes/%.*s/HEAD",
NULL
};
#define NUM_REV_PARSE_RULES (ARRAY_SIZE(ref_rev_parse_rules) - 1)
and then use something like
const int num_rules = NUM_REV_PARSE_RULES;
so that this dependency is more obvious if the ref_rev_parse_rules
convention changes later.
Alternatively, what would you think of using the simpler return
convention
return p - ref_rev_parse_rules + 1;
? Or even
return p - ref_rev_parse_rules;
and -1 for "no match"?
[...]
> --- 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;
Sensible and simple. If we wanted to make items earlier in the list
return a lower value from refname_match, then we'd need a !best_score
test here, which might be what motivates that return value convention.
[...]
> --- 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' '
Clearly illustrates the bug this fixes, in a way that makes it obvious
that a user would prefer the new behavior. Good.
With or without the tweak of introducing NUM_REV_PARSE_RULES mentioned
above,
Reviewed-by: Jonathan Nieder <jrnie...@gmail.com>
Thanks.
