fetch-pack: in protocol v2, reset in_vain upon ACK

In the function process_acks() in fetch-pack.c, the variable
received_ack is meant to track that an ACK was received, but it was
never set. This results in negotiation terminating prematurely through
the in_vain counter, when the counter should have been reset upon every
ACK.

Therefore, reset the in_vain counter upon every ACK.

Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fetch-pack.c b/fetch-pack.c
index 3891f8bb86bc6975f2060fc2fda4c9cf771915e0..10314df25b67ec415a427d6eaf617dec5e11d9a4 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1307,6 +1307,7 @@ static enum common_found process_acks(struct fetch_negotiator *negotiator,
 
                if (skip_prefix(reader->line, "ACK ", &arg)) {
                        struct object_id oid;
+                       received_ack = 1;
                        if (!get_oid_hex(arg, &oid)) {
                                struct commit *commit;
                                oidset_insert(common, &oid);

diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 95ed08db1b8a71044082fa5e99c96989be6c457f..fd39aad93ff989e16a531bfcb6719a9d6bc73032 100755 (executable)
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -403,6 +403,36 @@ test_expect_success 'in_vain not triggered before first ACK' '
        test_i18ngrep "Total 3 " trace
 '
 
+test_expect_success 'in_vain resetted upon ACK' '
+       rm -rf myserver myclient trace &&
+       git init myserver &&
+
+       # Linked list of commits on master. The first is common; the rest are
+       # not.
+       test_commit -C myserver first_master_commit &&
+       git clone "file://$(pwd)/myserver" myclient &&
+       test_commit_bulk -C myclient 255 &&
+
+       # Another linked list of commits on anotherbranch with no connection to
+       # master. The first is common; the rest are not.
+       git -C myserver checkout --orphan anotherbranch &&
+       test_commit -C myserver first_anotherbranch_commit &&
+       git -C myclient fetch origin anotherbranch:refs/heads/anotherbranch &&
+       git -C myclient checkout anotherbranch &&
+       test_commit_bulk -C myclient 255 &&
+
+       # The new commit that the client wants to fetch.
+       git -C myserver checkout master &&
+       test_commit -C myserver to_fetch &&
+
+       # The client will send (as "have"s) all 256 commits in anotherbranch
+       # first. The 256th commit is common between the client and the server,
+       # and should reset in_vain. This allows negotiation to continue until
+       # the client reports that first_anotherbranch_commit is common.
+       GIT_TRACE_PACKET="$(pwd)/trace" git -C myclient fetch --progress origin master &&
+       test_i18ngrep "Total 3 " trace
+'
+
 test_expect_success 'fetch in shallow repo unreachable shallow objects' '
        (
                git clone --bare --branch B --single-branch "file://$(pwd)/." no-reflog &&