Client-side protocol V2 support for fetching

Make all transports request protocol V2 when fetching. Depending on
the transport, set the GIT_PROTOCOL environment variable (file and
ssh), pass the Git-Protocol header (http), or set the hidden
"\0version=2\0" (git anon). We'll fall back to V0 if the server
doesn't reply with a version 2 answer.

A user can control which protocol the client requests via the git
config protocol.version; if not set, JGit requests protocol V2 for
fetching. Pushing always uses protocol V0 still.

In the API, there is only a new Transport.openFetch() version that
takes a collection of RefSpecs plus additional patterns to construct
the Ref prefixes for the "ls-refs" command in protocol V2. If none
are given, the server will still advertise all refs, even in protocol
V2.

BasePackConnection.readAdvertisedRefs() handles falling back to
protocol V0. It newly returns true if V0 was used and the advertised
refs were read, and false if V2 is used and an explicit "ls-refs" is
needed. (This can't be done transparently inside readAdvertisedRefs()
because a "stateless RPC" transport like TransportHttp may need to
open a new connection for writing.)

BasePackFetchConnection implements the changes needed for the protocol
V2 "fetch" command (stateless protocol, simplified ACK handling,
delimiters, section headers).

In TransportHttp, change readSmartHeaders() to also recognize the
"version 2" packet line as a valid smart server indication.

Adapt tests, and run all the HTTP tests not only with both HTTP
connection factories (JDK and Apache HttpClient) but also with both
protocol V0 and V2. The SSH tests are much slower and much more
focused on the SSH protocol and SSH key handling. Factor out two
very simple cloning and pulling tests and make those run with
protocol V2.

Bug: 553083
Change-Id: I357c7f5daa7efb2872f1c64ee6f6d54229031ae1
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

1 files changed, 13 insertions, 4 deletions

diff --git a/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/transport/sshd/SshdSession.java b/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/transport/sshd/SshdSession.java
index 0fb0610b99..5a50cc8f27 100644
--- a/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/transport/sshd/SshdSession.java
+++ b/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/transport/sshd/SshdSession.java
@@ -24,6 +24,7 @@ import java.util.Collections;
 import java.util.EnumSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
@@ -53,7 +54,7 @@ import org.eclipse.jgit.errors.TransportException;
 import org.eclipse.jgit.internal.transport.sshd.JGitSshClient;
 import org.eclipse.jgit.internal.transport.sshd.SshdText;
 import org.eclipse.jgit.transport.FtpChannel;
-import org.eclipse.jgit.transport.RemoteSession;
+import org.eclipse.jgit.transport.RemoteSession2;
 import org.eclipse.jgit.transport.SshConstants;
 import org.eclipse.jgit.transport.URIish;
 import org.eclipse.jgit.util.StringUtils;
@@ -61,11 +62,12 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * An implementation of {@link RemoteSession} based on Apache MINA sshd.
+ * An implementation of {@link org.eclipse.jgit.transport.RemoteSession
+ * RemoteSession} based on Apache MINA sshd.
  *
  * @since 5.2
  */
-public class SshdSession implements RemoteSession {
+public class SshdSession implements RemoteSession2 {
 
 	private static final Logger LOG = LoggerFactory
 			.getLogger(SshdSession.class);
@@ -290,8 +292,15 @@ public class SshdSession implements RemoteSession {
 
 	@Override
 	public Process exec(String commandName, int timeout) throws IOException {
+		return exec(commandName, Collections.emptyMap(), timeout);
+	}
+
+	@Override
+	public Process exec(String commandName, Map<String, String> environment,
+			int timeout) throws IOException {
 		@SuppressWarnings("resource")
-		ChannelExec exec = session.createExecChannel(commandName);
+		ChannelExec exec = session.createExecChannel(commandName, null,
+				environment);
 		if (timeout <= 0) {
 			try {
 				exec.open().verify();