Throw error when deepen-since excludes all commits

In C Git, when a client fetches with "git fetch --shallow-since=<date>
origin <ref>", and all commits reachable from <ref> are older than
<date>, the server dies with a message "no commits selected for shallow
requests". That is, (1) the --shallow-since filter applies to the commit
pointed to by the ref itself, and (2) there is a check that at least one
commit is not filtered out. (The pack-protocol.txt documentation does
not describe this, but the C implementation does this.)

The implementation in commit 1bb430dc21 ("UploadPack: support
deepen-since in protocol v2", 2018-09-27) does neither (1) nor (2), so
do both of these.

Change-Id: I9946327a71627626ecce34ca2d017d2add8867fc
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
index b74dcca583..ad3eb2e322 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
@@ -1280,6 +1280,26 @@ public class UploadPackTest {
 	}
 
 	@Test
+	public void testV2FetchShallowSince_noCommitsSelected() throws Exception {
+		PersonIdent person = new PersonIdent(remote.getRepository());
+
+		RevCommit tooOld = remote.commit()
+			.committer(new PersonIdent(person, 1500000000, 0)).create();
+
+		remote.update("branch1", tooOld);
+
+		thrown.expect(PackProtocolException.class);
+		thrown.expectMessage("No commits selected for shallow request");
+		uploadPackV2(
+			"command=fetch\n",
+			PacketLineIn.DELIM,
+			"deepen-since 1510000\n",
+			"want " + tooOld.toObjectId().getName() + "\n",
+			"done\n",
+			PacketLineIn.END);
+	}
+
+	@Test
 	public void testV2FetchUnrecognizedArgument() throws Exception {
 		thrown.expect(PackProtocolException.class);
 		thrown.expectMessage("unexpected invalid-argument");