fetch: do not pass ref-prefixes for fetch by exact SHA1

When v2.18.0-rc0~10^2~1 (refspec: consolidate ref-prefix generation
logic, 2018-05-16) factored out the ref-prefix generation code for
reuse, it left out the 'if (!item->exact_sha1)' test in the original
ref-prefix generation code. As a result, fetches by SHA-1 generate
ref-prefixes as though the SHA-1 being fetched were an abbreviated ref
name:

$ GIT_TRACE_PACKET=1 bin-wrappers/git -c protocol.version=2 \
fetch origin 12039e008f9a4e3394f3f94f8ea897785cb09448
[...]
packet:        fetch> ref-prefix 12039e008f9a4e3394f3f94f8ea897785cb09448
packet:        fetch> ref-prefix refs/12039e008f9a4e3394f3f94f8ea897785cb09448
packet:        fetch> ref-prefix refs/tags/12039e008f9a4e3394f3f94f8ea897785cb09448
packet:        fetch> ref-prefix refs/heads/12039e008f9a4e3394f3f94f8ea897785cb09448
packet:        fetch> ref-prefix refs/remotes/12039e008f9a4e3394f3f94f8ea897785cb09448
packet:        fetch> ref-prefix refs/remotes/12039e008f9a4e3394f3f94f8ea897785cb09448/HEAD
packet:        fetch> 0000

If there is another ref name on the command line or the object being
fetched is already available locally, then that's mostly harmless.
But otherwise, we error out with

fatal: no matching remote head

since the server did not send any refs we are interested in.  Filter
out the exact_sha1 refspecs to avoid this.

This patch adds a test to check this behavior that notices another
behavior difference between protocol v0 and v2 in the process.  Add a
NEEDSWORK comment to clear it up.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/refspec.c b/refspec.c
index c59a4ccf1e5d689b6f9cff00ee695a7ec4e40870..ada7854f7a6a55a783cf90574e1d759f5c3a661f 100644 (file)
--- a/refspec.c
+++ b/refspec.c
@@ -202,6 +202,8 @@ void refspec_ref_prefixes(const struct refspec *rs,
                const struct refspec_item *item = &rs->items[i];
                const char *prefix = NULL;
 
+               if (item->exact_sha1)
+                       continue;
                if (rs->fetch == REFSPEC_FETCH)
                        prefix = item->src;
                else if (item->dst)

diff --git a/refspec.h b/refspec.h
index 01b700e094f04459c2ddca8858bd558630a59966..3a9363887c48dbba612ae4de195c30f9d382c00c 100644 (file)
--- a/refspec.h
+++ b/refspec.h
@@ -42,6 +42,10 @@ void refspec_clear(struct refspec *rs);
 int valid_fetch_refspec(const char *refspec);
 
 struct argv_array;
+/*
+ * Determine what <prefix> values to pass to the peer in ref-prefix lines
+ * (see Documentation/technical/protocol-v2.txt).
+ */
 void refspec_ref_prefixes(const struct refspec *rs,
                          struct argv_array *ref_prefixes);
 

diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 82239138d585bb859a1f2f81394cb6b6d8313bf4..96c46587a510ed60ad33383de9cf43dc01bb862b 100755 (executable)
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1121,6 +1121,25 @@ test_expect_success 'fetch exact SHA1' '
        )
 '
 
+test_expect_success 'fetch exact SHA1 in protocol v2' '
+       mk_test testrepo heads/master hidden/one &&
+       git push testrepo master:refs/hidden/one &&
+       git -C testrepo config transfer.hiderefs refs/hidden &&
+       check_push_result testrepo $the_commit hidden/one &&
+
+       mk_child testrepo child &&
+       git -C child config protocol.version 2 &&
+
+       # make sure $the_commit does not exist here
+       git -C child repack -a -d &&
+       git -C child prune &&
+       test_must_fail git -C child cat-file -t $the_commit &&
+
+       # fetching the hidden object succeeds by default
+       # NEEDSWORK: should this match the v0 behavior instead?
+       git -C child fetch -v ../testrepo $the_commit:refs/heads/copy
+'
+
 for configallowtipsha1inwant in true false
 do
        test_expect_success "shallow fetch reachable SHA1 (but not a ref), allowtipsha1inwant=$configallowtipsha1inwant" '