@matheusbsbs / matheus-bagliano / commits / 6436a20284

refs: allow @{n} to work with n-sized reflog

This sequence works $ git checkout -b newbranch $ git commit --allow-empty -m one $ git show -s newbranch@{1} and shows the state that was immediately after the newbranch was created. But then if you do $ git reflog expire --expire=now refs/heads/newbranch $ git commit --allow=empty -m two $ git show -s newbranch@{1} you'd be scolded with fatal: log for 'newbranch' only has 1 entries While it is true that it has only 1 entry, we have enough information in that single entry that records the transition between the state in which the tip of the branch was pointing at commit 'one' to the new commit 'two' built on it, so we should be able to answer "what object newbranch was pointing at?". But we refuse to do so. Make @{0} the special case where we use the new side to look up that entry. Otherwise, look up @{n} using the old side of the (n-1)th entry of the reflog. Suggested-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Denton Liu committed Jan 7, 2021 at 02:36 UTC 6436a20284f33d42103cac93bd82e65bebb31526

3 files changed +47 -16

refs.c

+32 -14

@@ -900,40 +900,53 @@ static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,

900 const char *message, void *cb_data)

901 {

902 struct read_ref_at_cb *cb = cb_data;

903 + int reached_count;

904

905 cb->tz = tz;

906 cb->date = timestamp;

907

907 - if (timestamp <= cb->at_time || cb->cnt == 0) {

908 + /*

909 + * It is not possible for cb->cnt == 0 on the first iteration because

910 + * that special case is handled in read_ref_at().

911 + */

912 + if (cb->cnt > 0)

913 + cb->cnt--;

914 + reached_count = cb->cnt == 0 && !is_null_oid(ooid);

915 + if (timestamp <= cb->at_time || reached_count) {

916 set_read_ref_cutoffs(cb, timestamp, tz, message);

917 /*

918 * we have not yet updated cb->[n|o]oid so they still

919 * hold the values for the previous record.

920 */

913 - if (!is_null_oid(&cb->ooid)) {

914 - oidcpy(cb->oid, noid);

915 - if (!oideq(&cb->ooid, noid))

916 - warning(_("log for ref %s has gap after %s"),

921 + if (!is_null_oid(&cb->ooid) && !oideq(&cb->ooid, noid))

922 + warning(_("log for ref %s has gap after %s"),

923 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));

918 - }

919 - else if (cb->date == cb->at_time)

924 + if (reached_count)

925 + oidcpy(cb->oid, ooid);

926 + else if (!is_null_oid(&cb->ooid) || cb->date == cb->at_time)

927 oidcpy(cb->oid, noid);

928 else if (!oideq(noid, cb->oid))

929 warning(_("log for ref %s unexpectedly ended on %s"),

930 cb->refname, show_date(cb->date, cb->tz,

931 DATE_MODE(RFC2822)));

925 - cb->reccnt++;

926 - oidcpy(&cb->ooid, ooid);

927 - oidcpy(&cb->noid, noid);

932 cb->found_it = 1;

929 - return 1;

933 }

934 cb->reccnt++;

935 oidcpy(&cb->ooid, ooid);

936 oidcpy(&cb->noid, noid);

934 - if (cb->cnt > 0)

935 - cb->cnt--;

936 - return 0;

937 + return cb->found_it;

938 +}

939 +

940 +static int read_ref_at_ent_newest(struct object_id *ooid, struct object_id *noid,

941 + const char *email, timestamp_t timestamp,

942 + int tz, const char *message, void *cb_data)

943 +{

944 + struct read_ref_at_cb *cb = cb_data;

945 +

946 + set_read_ref_cutoffs(cb, timestamp, tz, message);

947 + oidcpy(cb->oid, noid);

948 + /* We just want the first entry */

949 + return 1;

950 }

951

952 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,

@@ -967,6 +980,11 @@ int read_ref_at(struct ref_store *refs, const char *refname,

980 cb.cutoff_cnt = cutoff_cnt;

981 cb.oid = oid;

982

983 + if (cb.cnt == 0) {

984 + refs_for_each_reflog_ent_reverse(refs, refname, read_ref_at_ent_newest, &cb);

985 + return 0;

986 + }

987 +

988 refs_for_each_reflog_ent_reverse(refs, refname, read_ref_at_ent, &cb);

989

990 if (!cb.reccnt) {

t/t1503-rev-parse-verify.sh

+2 -2

@@ -86,8 +86,8 @@ test_expect_success 'fails silently when using -q' '

86 test_expect_success 'fails silently when using -q with deleted reflogs' '

87 ref=$(git rev-parse HEAD) &&

88 git update-ref --create-reflog -m "message for refs/test" refs/test "$ref" &&

89 - git reflog delete --updateref --rewrite refs/test@{0} &&

90 - test_must_fail git rev-parse -q --verify refs/test@{0} >error 2>&1 &&

89 + git reflog delete --updateref --rewrite refs/test@{1} &&

90 + test_must_fail git rev-parse -q --verify refs/test@{1} >error 2>&1 &&

91 test_must_be_empty error

92 '

t/t1508-at-combinations.sh

+13

@@ -99,4 +99,17 @@ test_expect_success 'create path with @' '

99 check "@:normal" blob content

100 check "@:fun@ny" blob content

101

102 +test_expect_success '@{1} works with only one reflog entry' '

103 + git checkout -B newbranch master &&

104 + git reflog expire --expire=now refs/heads/newbranch &&

105 + git commit --allow-empty -m "first after expiration" &&

106 + test_cmp_rev newbranch~ newbranch@{1}

107 +'

108 +

109 +test_expect_success '@{0} works with empty reflog' '

110 + git checkout -B newbranch master &&

111 + git reflog expire --expire=now refs/heads/newbranch &&

112 + test_cmp_rev newbranch newbranch@{0}

113 +'

114 +

115 test_done