t5616: cover case of client having delta base

When fetching into a partial clone, Git first prefetches missing
REF_DELTA bases from the promisor remote. (This feature was introduced
in [1].) But as can be seen in a recent test coverage report [2], the
case in which a REF_DELTA base is already present is not covered by
tests.

Extend the tests slightly to cover this case.

[1] 8a30a1efd1 ("index-pack: prefetch missing REF_DELTA bases",
2019-05-15).
[2] https://public-inbox.org/git/396091fc-5572-19a5-4f18-61c258590dd5@gmail.com/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh
index 8b9b471a62753794d8304a8c9e9902a7bc4a0241..b91ef548f86b0e250b8fdcd1b8b764c780218931 100755 (executable)
--- a/t/t5616-partial-clone.sh
+++ b/t/t5616-partial-clone.sh
@@ -346,30 +346,37 @@ test_expect_success 'tolerate server sending REF_DELTA against missing promisor
        test_config -C "$SERVER" uploadpack.allowfilter 1 &&
        test_config -C "$SERVER" uploadpack.allowanysha1inwant 1 &&
 
-       # Create a commit with a blob to be used as a delta base.
+       # Create a commit with 2 blobs to be used as delta bases.
        for i in $(test_seq 10)
        do
-               echo "this is a line" >>"$SERVER/foo.txt"
+               echo "this is a line" >>"$SERVER/foo.txt" &&
+               echo "this is another line" >>"$SERVER/have.txt"
        done &&
-       git -C "$SERVER" add foo.txt &&
+       git -C "$SERVER" add foo.txt have.txt &&
        git -C "$SERVER" commit -m bar &&
-       git -C "$SERVER" rev-parse HEAD:foo.txt >deltabase &&
+       git -C "$SERVER" rev-parse HEAD:foo.txt >deltabase_missing &&
+       git -C "$SERVER" rev-parse HEAD:have.txt >deltabase_have &&
 
+       # Clone. The client has deltabase_have but not deltabase_missing.
        git -c protocol.version=2 clone --no-checkout \
                --filter=blob:none $HTTPD_URL/one_time_sed/server repo &&
+       git -C repo hash-object -w -- "$SERVER/have.txt" &&
 
-       # Sanity check to ensure that the client does not have that blob.
+       # Sanity check to ensure that the client does not have
+       # deltabase_missing.
        git -C repo rev-list --objects --ignore-missing \
-               -- $(cat deltabase) >objlist &&
+               -- $(cat deltabase_missing) >objlist &&
        test_line_count = 0 objlist &&
 
        # Another commit. This commit will be fetched by the client.
        echo "abcdefghijklmnopqrstuvwxyz" >>"$SERVER/foo.txt" &&
-       git -C "$SERVER" add foo.txt &&
+       echo "abcdefghijklmnopqrstuvwxyz" >>"$SERVER/have.txt" &&
+       git -C "$SERVER" add foo.txt have.txt &&
        git -C "$SERVER" commit -m baz &&
 
        # Pack a thin pack containing, among other things, HEAD:foo.txt
-       # delta-ed against HEAD^:foo.txt.
+       # delta-ed against HEAD^:foo.txt and HEAD:have.txt delta-ed against
+       # HEAD^:have.txt.
        printf "%s\n--not\n%s\n" \
                $(git -C "$SERVER" rev-parse HEAD) \
                $(git -C "$SERVER" rev-parse HEAD^) |
@@ -381,8 +388,13 @@ test_expect_success 'tolerate server sending REF_DELTA against missing promisor
        # most significant nybble of the first byte is 0b1111 (0b1 to indicate
        # that the header continues, and 0b111 to indicate REF_DELTA), followed
        # by any 3 nybbles, then the OID of the delta base.
-       git -C "$SERVER" rev-parse HEAD^:foo.txt >deltabase &&
-       printf "f.,..%s" $(intersperse "," <deltabase) >want &&
+       printf "f.,..%s" $(intersperse "," <deltabase_missing) >want &&
+       hex_unpack <thin.pack | intersperse "," >have &&
+       grep $(cat want) have &&
+
+       # Ensure that the pack contains one delta against HEAD^:have.txt,
+       # similar to the above.
+       printf "f.,..%s" $(intersperse "," <deltabase_have) >want &&
        hex_unpack <thin.pack | intersperse "," >have &&
        grep $(cat want) have &&
 
@@ -394,7 +406,12 @@ test_expect_success 'tolerate server sending REF_DELTA against missing promisor
 
        # Fetch the thin pack and ensure that index-pack is able to handle the
        # REF_DELTA object with a missing promisor delta base.
-       git -C repo -c protocol.version=2 fetch &&
+       GIT_TRACE_PACKET="$(pwd)/trace" git -C repo -c protocol.version=2 fetch &&
+
+       # Ensure that the missing delta base was directly fetched, but not the
+       # one that the client has.
+       grep "want $(cat deltabase_missing)" trace &&
+       ! grep "want $(cat deltabase_have)" trace &&
 
        # Ensure that the one-time-sed script was used.
        ! test -e "$HTTPD_ROOT_PATH/one-time-sed"