update-ref: fix streaming of status updates
When executing git-update-ref(1) with the `--stdin` flag, then the user can queue updates and, since e48cf33b61 (update-ref: implement interactive transaction handling, 2020-04-02), interactively drive the transaction's state via a set of transactional verbs. This interactivity is somewhat broken though: while the caller can use these verbs to drive the transaction's state, the status messages which confirm that a verb has been processed is not flushed. The caller may thus be left hanging waiting for the acknowledgement. Fix the bug by flushing stdout after writing the status update. Add a test which catches this bug. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt committed
Sep 3, 2021 at 11:06 UTC
efa3d64ce86a600563c8bf909c46dd0985ee6c11
2 files changed
+42
-4
builtin/update-ref.c
+10
-4
@@ -302,6 +302,12 @@ static void parse_cmd_verify(struct ref_transaction *transaction,
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strbuf_release(&err);
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}
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+static void report_ok(const char *command)
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+{
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+ fprintf(stdout, "%s: ok\n", command);
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+ fflush(stdout);
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+}
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+
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static void parse_cmd_option(struct ref_transaction *transaction,
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const char *next, const char *end)
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{
@@ -317,7 +323,7 @@ static void parse_cmd_start(struct ref_transaction *transaction,
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{
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if (*next != line_termination)
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die("start: extra input: %s", next);
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- puts("start: ok");
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+ report_ok("start");
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}
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static void parse_cmd_prepare(struct ref_transaction *transaction,
@@ -328,7 +334,7 @@ static void parse_cmd_prepare(struct ref_transaction *transaction,
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die("prepare: extra input: %s", next);
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if (ref_transaction_prepare(transaction, &error))
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die("prepare: %s", error.buf);
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- puts("prepare: ok");
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+ report_ok("prepare");
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}
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static void parse_cmd_abort(struct ref_transaction *transaction,
@@ -339,7 +345,7 @@ static void parse_cmd_abort(struct ref_transaction *transaction,
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die("abort: extra input: %s", next);
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if (ref_transaction_abort(transaction, &error))
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die("abort: %s", error.buf);
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- puts("abort: ok");
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+ report_ok("abort");
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}
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static void parse_cmd_commit(struct ref_transaction *transaction,
@@ -350,7 +356,7 @@ static void parse_cmd_commit(struct ref_transaction *transaction,
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die("commit: extra input: %s", next);
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if (ref_transaction_commit(transaction, &error))
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die("commit: %s", error.buf);
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- puts("commit: ok");
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+ report_ok("commit");
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ref_transaction_free(transaction);
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}
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t/t1400-update-ref.sh
+32
@@ -1598,6 +1598,38 @@ test_expect_success 'transaction cannot restart ongoing transaction' '
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test_must_fail git show-ref --verify refs/heads/restart
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'
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+test_expect_success PIPE 'transaction flushes status updates' '
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+ mkfifo in out &&
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+ (git update-ref --stdin <in >out &) &&
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+
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+ exec 9>in &&
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+ test_when_finished "exec 9>&-" &&
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+
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+ echo "start" >&9 &&
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+ echo "start: ok" >expected &&
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+ read line <out &&
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+ echo "$line" >actual &&
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+ test_cmp expected actual &&
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+
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+ echo "create refs/heads/flush $A" >&9 &&
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+
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+ echo prepare >&9 &&
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+ echo "prepare: ok" >expected &&
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+ read line <out &&
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+ echo "$line" >actual &&
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+ test_cmp expected actual &&
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+
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+ # This must now fail given that we have locked the ref.
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+ test_must_fail git update-ref refs/heads/flush $B 2>stderr &&
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+ grep "fatal: update_ref failed for ref ${SQ}refs/heads/flush${SQ}: cannot lock ref" stderr &&
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+
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+ echo commit >&9 &&
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+ echo "commit: ok" >expected &&
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+ read line <out &&
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+ echo "$line" >actual &&
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+ test_cmp expected actual
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+'
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+
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test_expect_success 'directory not created deleting packed ref' '
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git branch d1/d2/r1 HEAD &&
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git pack-refs --all &&