Allow users to show server messages while pushing

Allow users to provide their OutputStream (via Transport#
push(monitor, refUpdates, out)) so that server messages can be written
to it (in SideBandInputStream) while they're coming in.

CQ: 7065
Bug: 398404
Change-Id: I670782784b38702d52bca98203909aca0496d1c0
Signed-off-by: Andre Dietisheim <andre.dietisheim@gmail.com>
Signed-off-by: Chris Aniszczyk <zx@twitter.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

13 files changed, 300 insertions, 27 deletions

diff --git a/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HookMessageTest.java b/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HookMessageTest.java
index c9045763c6..155a43399c 100644
--- a/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HookMessageTest.java
+++ b/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HookMessageTest.java
@@ -47,6 +47,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -180,4 +182,40 @@ public class HookMessageTest extends HttpTestCase {
 				+ "come back next year!\n", //
 				result.getMessages());
 	}
+
+	@Test
+	public void testPush_HookMessagesToOutputStream() throws Exception {
+		final TestRepository src = createTestRepository();
+		final RevBlob Q_txt = src.blob("new text");
+		final RevCommit Q = src.commit().add("Q", Q_txt).create();
+		final Repository db = src.getRepository();
+		final String dstName = Constants.R_HEADS + "new.branch";
+		Transport t;
+		PushResult result;
+
+		t = Transport.open(db, remoteURI);
+		OutputStream out = new ByteArrayOutputStream();
+		try {
+			final String srcExpr = Q.name();
+			final boolean forceUpdate = false;
+			final String localName = null;
+			final ObjectId oldId = null;
+
+			RemoteRefUpdate update = new RemoteRefUpdate(src.getRepository(),
+					srcExpr, dstName, forceUpdate, localName, oldId);
+			result = t.push(NullProgressMonitor.INSTANCE,
+					Collections.singleton(update), out);
+		} finally {
+			t.close();
+		}
+
+		String expectedMessage = "message line 1\n" //
+				+ "error: no soup for you!\n" //
+				+ "come back next year!\n";
+		assertEquals(expectedMessage, //
+				result.getMessages());
+
+		assertEquals(expectedMessage, out.toString());
+	}
+
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PushProcessTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PushProcessTest.java
index 69824b2138..e523db981a 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PushProcessTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PushProcessTest.java
@@ -48,6 +48,7 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
+import java.io.OutputStream;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -432,6 +433,12 @@ public class PushProcessTest extends SampleDataRepositoryTestCase {
 		}
 
 		public void push(ProgressMonitor monitor,
+				Map<String, RemoteRefUpdate> refsToUpdate, OutputStream out)
+				throws TransportException {
+			push(monitor, refsToUpdate);
+		}
+
+		public void push(ProgressMonitor monitor,
 				Map<String, RemoteRefUpdate> refsToUpdate)
 				throws TransportException {
 			for (final RemoteRefUpdate rru : refsToUpdate.values()) {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/PushCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/PushCommand.java
index 1a4058e12d..c719f0a546 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/PushCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/PushCommand.java
@@ -43,6 +43,7 @@
 package org.eclipse.jgit.api;
 
 import java.io.IOException;
+import java.io.OutputStream;
 import java.net.URISyntaxException;
 import java.text.MessageFormat;
 import java.util.ArrayList;
@@ -92,6 +93,8 @@ public class PushCommand extends
 
 	private boolean thin = Transport.DEFAULT_PUSH_THIN;
 
+	private OutputStream out;
+
 	/**
 	 * @param repo
 	 */
@@ -150,7 +153,7 @@ public class PushCommand extends
 						.findRemoteRefUpdatesFor(refSpecs);
 
 				try {
-					PushResult result = transport.push(monitor, toPush);
+					PushResult result = transport.push(monitor, toPush, out);
 					pushResults.add(result);
 
 				} catch (TransportException e) {
@@ -404,4 +407,16 @@ public class PushCommand extends
 		this.force = force;
 		return this;
 	}
+
+	/**
+	 * Sets the output stream to write sideband messages to
+	 *
+	 * @param out
+	 * @return {@code this}
+	 * @since 3.0
+	 */
+	public PushCommand setOutputStream(OutputStream out) {
+		this.out = out;
+		return this;
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseFetchConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseFetchConnection.java
index b77e644a25..cc2770771e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseFetchConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseFetchConnection.java
@@ -45,6 +45,7 @@
 
 package org.eclipse.jgit.transport;
 
+import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Set;
 
@@ -66,6 +67,12 @@ abstract class BaseFetchConnection extends BaseConnection implements
 	public final void fetch(final ProgressMonitor monitor,
 			final Collection<Ref> want, final Set<ObjectId> have)
 			throws TransportException {
+		fetch(monitor, want, have, null);
+	}
+
+	public final void fetch(final ProgressMonitor monitor,
+			final Collection<Ref> want, final Set<ObjectId> have,
+			OutputStream out) throws TransportException {
 		markStartedOperation();
 		doFetch(monitor, want, have);
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackFetchConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackFetchConnection.java
index 4b1411ab66..c82a0cde81 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackFetchConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackFetchConnection.java
@@ -47,6 +47,7 @@ package org.eclipse.jgit.transport;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.text.MessageFormat;
 import java.util.Collection;
 import java.util.Collections;
@@ -59,13 +60,13 @@ import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.internal.storage.file.PackLock;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.Config.SectionParser;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.MutableObjectId;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
-import org.eclipse.jgit.lib.Config.SectionParser;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevCommitList;
 import org.eclipse.jgit.revwalk.RevFlag;
@@ -265,8 +266,17 @@ public abstract class BasePackFetchConnection extends BasePackConnection
 	public final void fetch(final ProgressMonitor monitor,
 			final Collection<Ref> want, final Set<ObjectId> have)
 			throws TransportException {
+		fetch(monitor, want, have, null);
+	}
+
+	/**
+	 * @since 3.0
+	 */
+	public final void fetch(final ProgressMonitor monitor,
+			final Collection<Ref> want, final Set<ObjectId> have,
+			OutputStream outputStream) throws TransportException {
 		markStartedOperation();
-		doFetch(monitor, want, have);
+		doFetch(monitor, want, have, outputStream);
 	}
 
 	public boolean didFetchIncludeTags() {
@@ -298,12 +308,15 @@ public abstract class BasePackFetchConnection extends BasePackConnection
 	 *            additional objects to assume that already exist locally. This
 	 *            will be added to the set of objects reachable from the
 	 *            destination repository's references.
+	 * @param outputStream
+	 *            ouputStream to write sideband messages to
 	 * @throws TransportException
 	 *             if any exception occurs.
+	 * @since 3.0
 	 */
 	protected void doFetch(final ProgressMonitor monitor,
-			final Collection<Ref> want, final Set<ObjectId> have)
-			throws TransportException {
+			final Collection<Ref> want, final Set<ObjectId> have,
+			OutputStream outputStream) throws TransportException {
 		try {
 			markRefsAdvertised();
 			markReachable(have, maxTimeWanted(want));
@@ -321,7 +334,7 @@ public abstract class BasePackFetchConnection extends BasePackConnection
 				state = null;
 				pckState = null;
 
-				receivePack(monitor);
+				receivePack(monitor, outputStream);
 			}
 		} catch (CancelledException ce) {
 			close();
@@ -702,11 +715,13 @@ public abstract class BasePackFetchConnection extends BasePackConnection
 			((RevCommit) obj).carry(COMMON);
 	}
 
-	private void receivePack(final ProgressMonitor monitor) throws IOException {
+	private void receivePack(final ProgressMonitor monitor,
+			OutputStream outputStream) throws IOException {
 		onReceivePack();
 		InputStream input = in;
 		if (sideband)
-			input = new SideBandInputStream(input, monitor, getMessageWriter());
+			input = new SideBandInputStream(input, monitor, getMessageWriter(),
+					outputStream);
 
 		ObjectInserter ins = local.newObjectInserter();
 		try {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackPushConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackPushConnection.java
index b748d00a77..60985e7c28 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackPushConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackPushConnection.java
@@ -45,6 +45,7 @@
 package org.eclipse.jgit.transport;
 
 import java.io.IOException;
+import java.io.OutputStream;
 import java.text.MessageFormat;
 import java.util.Collection;
 import java.util.HashSet;
@@ -138,8 +139,17 @@ public abstract class BasePackPushConnection extends BasePackConnection implemen
 	public void push(final ProgressMonitor monitor,
 			final Map<String, RemoteRefUpdate> refUpdates)
 			throws TransportException {
+		push(monitor, refUpdates, null);
+	}
+
+	/**
+	 * @since 3.0
+	 */
+	public void push(final ProgressMonitor monitor,
+			final Map<String, RemoteRefUpdate> refUpdates, OutputStream outputStream)
+			throws TransportException {
 		markStartedOperation();
-		doPush(monitor, refUpdates);
+		doPush(monitor, refUpdates, outputStream);
 	}
 
 	@Override
@@ -172,14 +182,17 @@ public abstract class BasePackPushConnection extends BasePackConnection implemen
 	 *            progress monitor to receive status updates.
 	 * @param refUpdates
 	 *            update commands to be applied to the remote repository.
+	 * @param outputStream
+	 *            output stream to write sideband messages to
 	 * @throws TransportException
 	 *             if any exception occurs.
+	 * @since 3.0
 	 */
 	protected void doPush(final ProgressMonitor monitor,
-			final Map<String, RemoteRefUpdate> refUpdates)
-			throws TransportException {
+			final Map<String, RemoteRefUpdate> refUpdates,
+			OutputStream outputStream) throws TransportException {
 		try {
-			writeCommands(refUpdates.values(), monitor);
+			writeCommands(refUpdates.values(), monitor, outputStream);
 			if (writePack)
 				writePack(refUpdates, monitor);
 			if (sentCommand) {
@@ -208,8 +221,8 @@ public abstract class BasePackPushConnection extends BasePackConnection implemen
 	}
 
 	private void writeCommands(final Collection<RemoteRefUpdate> refUpdates,
-			final ProgressMonitor monitor) throws IOException {
-		final String capabilities = enableCapabilities(monitor);
+			final ProgressMonitor monitor, OutputStream outputStream) throws IOException {
+		final String capabilities = enableCapabilities(monitor, outputStream);
 		for (final RemoteRefUpdate rru : refUpdates) {
 			if (!capableDeleteRefs && rru.isDelete()) {
 				rru.setStatus(Status.REJECTED_NODELETE);
@@ -242,7 +255,8 @@ public abstract class BasePackPushConnection extends BasePackConnection implemen
 		outNeedsEnd = false;
 	}
 
-	private String enableCapabilities(final ProgressMonitor monitor) {
+	private String enableCapabilities(final ProgressMonitor monitor,
+			OutputStream outputStream) {
 		final StringBuilder line = new StringBuilder();
 		capableReport = wantCapability(line, CAPABILITY_REPORT_STATUS);
 		capableDeleteRefs = wantCapability(line, CAPABILITY_DELETE_REFS);
@@ -250,7 +264,8 @@ public abstract class BasePackPushConnection extends BasePackConnection implemen
 
 		capableSideBand = wantCapability(line, CAPABILITY_SIDE_BAND_64K);
 		if (capableSideBand) {
-			in = new SideBandInputStream(in, monitor, getMessageWriter());
+			in = new SideBandInputStream(in, monitor, getMessageWriter(),
+					outputStream);
 			pckIn = new PacketLineIn(in);
 		}
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchConnection.java
index ef8e7d74d5..2d042400f6 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchConnection.java
@@ -46,6 +46,7 @@
 
 package org.eclipse.jgit.transport;
 
+import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Set;
 
@@ -112,6 +113,47 @@ public interface FetchConnection extends Connection {
 			throws TransportException;
 
 	/**
+	 * Fetch objects we don't have but that are reachable from advertised refs.
+	 * <p>
+	 * Only one call per connection is allowed. Subsequent calls will result in
+	 * {@link TransportException}.
+	 * </p>
+	 * <p>
+	 * Implementations are free to use network connections as necessary to
+	 * efficiently (for both client and server) transfer objects from the remote
+	 * repository into this repository. When possible implementations should
+	 * avoid replacing/overwriting/duplicating an object already available in
+	 * the local destination repository. Locally available objects and packs
+	 * should always be preferred over remotely available objects and packs.
+	 * {@link Transport#isFetchThin()} should be honored if applicable.
+	 * </p>
+	 *
+	 * @param monitor
+	 *            progress monitor to inform the end-user about the amount of
+	 *            work completed, or to indicate cancellation. Implementations
+	 *            should poll the monitor at regular intervals to look for
+	 *            cancellation requests from the user.
+	 * @param want
+	 *            one or more refs advertised by this connection that the caller
+	 *            wants to store locally.
+	 * @param have
+	 *            additional objects known to exist in the destination
+	 *            repository, especially if they aren't yet reachable by the ref
+	 *            database. Connections should take this set as an addition to
+	 *            what is reachable through all Refs, not in replace of it.
+	 * @param out
+	 *            OutputStream to write sideband messages to
+	 * @throws TransportException
+	 *             objects could not be copied due to a network failure,
+	 *             protocol error, or error on remote side, or connection was
+	 *             already used for fetch.
+	 * @since 3.0
+	 */
+	public void fetch(final ProgressMonitor monitor,
+			final Collection<Ref> want, final Set<ObjectId> have,
+			OutputStream out) throws TransportException;
+
+	/**
 	 * Did the last {@link #fetch(ProgressMonitor, Collection, Set)} get tags?
 	 * <p>
 	 * Some Git aware transports are able to implicitly grab an annotated tag if
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushConnection.java
index 489ac78874..c2a885f622 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushConnection.java
@@ -44,6 +44,7 @@
 
 package org.eclipse.jgit.transport;
 
+import java.io.OutputStream;
 import java.util.Map;
 
 import org.eclipse.jgit.errors.TransportException;
@@ -111,4 +112,50 @@ public interface PushConnection extends Connection {
 	public void push(final ProgressMonitor monitor,
 			final Map<String, RemoteRefUpdate> refUpdates)
 			throws TransportException;
+
+	/**
+	 * Pushes to the remote repository basing on provided specification. This
+	 * possibly result in update/creation/deletion of refs on remote repository
+	 * and sending objects that remote repository need to have a consistent
+	 * objects graph from new refs.
+	 * <p>
+	 * <p>
+	 * Only one call per connection is allowed. Subsequent calls will result in
+	 * {@link TransportException}.
+	 * </p>
+	 * <p>
+	 * Implementation may use local repository to send a minimum set of objects
+	 * needed by remote repository in efficient way.
+	 * {@link Transport#isPushThin()} should be honored if applicable.
+	 * refUpdates should be filled with information about status of each update.
+	 * </p>
+	 *
+	 * @param monitor
+	 *            progress monitor to update the end-user about the amount of
+	 *            work completed, or to indicate cancellation. Implementors
+	 *            should poll the monitor at regular intervals to look for
+	 *            cancellation requests from the user.
+	 * @param refUpdates
+	 *            map of remote refnames to remote refs update
+	 *            specifications/statuses. Can't be empty. This indicate what
+	 *            refs caller want to update on remote side. Only refs updates
+	 *            with {@link Status#NOT_ATTEMPTED} should passed.
+	 *            Implementation must ensure that and appropriate status with
+	 *            optional message should be set during call. No refUpdate with
+	 *            {@link Status#AWAITING_REPORT} or {@link Status#NOT_ATTEMPTED}
+	 *            can be leaved by implementation after return from this call.
+	 * @param out
+	 *            output stream to write sideband messages to
+	 * @throws TransportException
+	 *             objects could not be copied due to a network failure,
+	 *             critical protocol error, or error on remote side, or
+	 *             connection was already used for push - new connection must be
+	 *             created. Non-critical errors concerning only isolated refs
+	 *             should be placed in refUpdates.
+	 * @since 3.0
+	 */
+	public void push(final ProgressMonitor monitor,
+			final Map<String, RemoteRefUpdate> refUpdates, OutputStream out)
+			throws TransportException;
+
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushProcess.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushProcess.java
index 3169bfc230..53fba55572 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushProcess.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PushProcess.java
@@ -44,6 +44,7 @@
 package org.eclipse.jgit.transport;
 
 import java.io.IOException;
+import java.io.OutputStream;
 import java.text.MessageFormat;
 import java.util.Collection;
 import java.util.HashMap;
@@ -64,7 +65,7 @@ import org.eclipse.jgit.transport.RemoteRefUpdate.Status;
 /**
  * Class performing push operation on remote repository.
  *
- * @see Transport#push(ProgressMonitor, Collection)
+ * @see Transport#push(ProgressMonitor, Collection, OutputStream)
  */
 class PushProcess {
 	/** Task name for {@link ProgressMonitor} used during opening connection. */
@@ -82,6 +83,9 @@ class PushProcess {
 	/** Revision walker for checking some updates properties. */
 	private final RevWalk walker;
 
+	/** an outputstream to write messages to */
+	private final OutputStream out;
+
 	/**
 	 * Create process for specified transport and refs updates specification.
 	 *
@@ -90,13 +94,33 @@ class PushProcess {
 	 *            connection.
 	 * @param toPush
 	 *            specification of refs updates (and local tracking branches).
+	 *
 	 * @throws TransportException
 	 */
 	PushProcess(final Transport transport,
 			final Collection<RemoteRefUpdate> toPush) throws TransportException {
+		this(transport, toPush, null);
+	}
+
+	/**
+	 * Create process for specified transport and refs updates specification.
+	 * 
+	 * @param transport
+	 *            transport between remote and local repository, used to create
+	 *            connection.
+	 * @param toPush
+	 *            specification of refs updates (and local tracking branches).
+	 * @param out
+	 *            OutputStream to write messages to
+	 * @throws TransportException
+	 */
+	PushProcess(final Transport transport,
+			final Collection<RemoteRefUpdate> toPush, OutputStream out)
+			throws TransportException {
 		this.walker = new RevWalk(transport.local);
 		this.transport = transport;
 		this.toPush = new HashMap<String, RemoteRefUpdate>();
+		this.out = out;
 		for (final RemoteRefUpdate rru : toPush) {
 			if (this.toPush.put(rru.getRemoteName(), rru) != null)
 				throw new TransportException(MessageFormat.format(
@@ -138,7 +162,7 @@ class PushProcess {
 				if (transport.isDryRun())
 					modifyUpdatesForDryRun();
 				else if (!preprocessed.isEmpty())
-					connection.push(monitor, preprocessed);
+					connection.push(monitor, preprocessed, out);
 			} finally {
 				connection.close();
 				res.addMessages(connection.getMessages());
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/SideBandInputStream.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/SideBandInputStream.java
index b48a8a5f09..cf388e2718 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/SideBandInputStream.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/SideBandInputStream.java
@@ -48,6 +48,7 @@ import static org.eclipse.jgit.transport.SideBandOutputStream.HDR_SIZE;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.Writer;
 import java.text.MessageFormat;
 import java.util.regex.Matcher;
@@ -99,6 +100,8 @@ class SideBandInputStream extends InputStream {
 
 	private final Writer messages;
 
+	private final OutputStream out;
+
 	private String progressBuffer = ""; //$NON-NLS-1$
 
 	private String currentTask;
@@ -112,12 +115,13 @@ class SideBandInputStream extends InputStream {
 	private int available;
 
 	SideBandInputStream(final InputStream in, final ProgressMonitor progress,
-			final Writer messageStream) {
+			final Writer messageStream, OutputStream outputStream) {
 		rawIn = in;
 		pckIn = new PacketLineIn(rawIn);
 		monitor = progress;
 		messages = messageStream;
 		currentTask = ""; //$NON-NLS-1$
+		out = outputStream;
 	}
 
 	@Override
@@ -232,6 +236,8 @@ class SideBandInputStream extends InputStream {
 		}
 
 		messages.write(msg);
+		if (out != null)
+			out.write(msg.getBytes());
 	}
 
 	private void beginTask(final int totalWorkUnits) {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java
index 5a7c0a194e..3c196109d7 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java
@@ -50,6 +50,7 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.io.OutputStream;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -1134,6 +1135,8 @@ public abstract class Transport {
 	 *            converted by {@link #findRemoteRefUpdatesFor(Collection)}. No
 	 *            more than 1 RemoteRefUpdate with the same remoteName is
 	 *            allowed. These objects are modified during this call.
+	 * @param out
+	 *            output stream to write messages to
 	 * @return information about results of remote refs updates, tracking refs
 	 *         updates and refs advertised by remote repository.
 	 * @throws NotSupportedException
@@ -1143,9 +1146,11 @@ public abstract class Transport {
 	 *             the remote connection could not be established or object
 	 *             copying (if necessary) failed at I/O or protocol level or
 	 *             update specification was incorrect.
+	 * @since 3.0
 	 */
 	public PushResult push(final ProgressMonitor monitor,
-			Collection<RemoteRefUpdate> toPush) throws NotSupportedException,
+			Collection<RemoteRefUpdate> toPush, OutputStream out)
+			throws NotSupportedException,
 			TransportException {
 		if (toPush == null || toPush.isEmpty()) {
 			// If the caller did not ask for anything use the defaults.
@@ -1158,11 +1163,57 @@ public abstract class Transport {
 			if (toPush.isEmpty())
 				throw new TransportException(JGitText.get().nothingToPush);
 		}
-		final PushProcess pushProcess = new PushProcess(this, toPush);
+		final PushProcess pushProcess = new PushProcess(this, toPush, out);
 		return pushProcess.execute(monitor);
 	}
 
 	/**
+	 * Push objects and refs from the local repository to the remote one.
+	 * <p>
+	 * This is a utility function providing standard push behavior. It updates
+	 * remote refs and sends necessary objects according to remote ref update
+	 * specification. After successful remote ref update, associated locally
+	 * stored tracking branch is updated if set up accordingly. Detailed
+	 * operation result is provided after execution.
+	 * <p>
+	 * For setting up remote ref update specification from ref spec, see helper
+	 * method {@link #findRemoteRefUpdatesFor(Collection)}, predefined refspecs
+	 * ({@link #REFSPEC_TAGS}, {@link #REFSPEC_PUSH_ALL}) or consider using
+	 * directly {@link RemoteRefUpdate} for more possibilities.
+	 * <p>
+	 * When {@link #isDryRun()} is true, result of this operation is just
+	 * estimation of real operation result, no real action is performed.
+	 *
+	 * @see RemoteRefUpdate
+	 *
+	 * @param monitor
+	 *            progress monitor to inform the user about our processing
+	 *            activity. Must not be null. Use {@link NullProgressMonitor} if
+	 *            progress updates are not interesting or necessary.
+	 * @param toPush
+	 *            specification of refs to push. May be null or the empty
+	 *            collection to use the specifications from the RemoteConfig
+	 *            converted by {@link #findRemoteRefUpdatesFor(Collection)}. No
+	 *            more than 1 RemoteRefUpdate with the same remoteName is
+	 *            allowed. These objects are modified during this call.
+	 *
+	 * @return information about results of remote refs updates, tracking refs
+	 *         updates and refs advertised by remote repository.
+	 * @throws NotSupportedException
+	 *             this transport implementation does not support pushing
+	 *             objects.
+	 * @throws TransportException
+	 *             the remote connection could not be established or object
+	 *             copying (if necessary) failed at I/O or protocol level or
+	 *             update specification was incorrect.
+	 */
+	public PushResult push(final ProgressMonitor monitor,
+			Collection<RemoteRefUpdate> toPush) throws NotSupportedException,
+			TransportException {
+		return push(monitor, toPush, null);
+	}
+
+	/**
 	 * Convert push remote refs update specification from {@link RefSpec} form
 	 * to {@link RemoteRefUpdate}. Conversion expands wildcards by matching
 	 * source part to local refs. expectedOldObjectId in RemoteRefUpdate is
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportHttp.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportHttp.java
index 9816d97808..baaf8867e4 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportHttp.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportHttp.java
@@ -739,12 +739,12 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 
 		@Override
 		protected void doFetch(final ProgressMonitor monitor,
-				final Collection<Ref> want, final Set<ObjectId> have)
-				throws TransportException {
+				final Collection<Ref> want, final Set<ObjectId> have,
+				final OutputStream outputStream) throws TransportException {
 			try {
 				svc = new MultiRequestService(SVC_UPLOAD_PACK);
 				init(svc.getInputStream(), svc.getOutputStream());
-				super.doFetch(monitor, want, have);
+				super.doFetch(monitor, want, have, outputStream);
 			} finally {
 				svc = null;
 			}
@@ -768,11 +768,11 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 		}
 
 		protected void doPush(final ProgressMonitor monitor,
-				final Map<String, RemoteRefUpdate> refUpdates)
-				throws TransportException {
+				final Map<String, RemoteRefUpdate> refUpdates,
+				OutputStream outputStream) throws TransportException {
 			final Service svc = new MultiRequestService(SVC_RECEIVE_PACK);
 			init(svc.getInputStream(), svc.getOutputStream());
-			super.doPush(monitor, refUpdates);
+			super.doPush(monitor, refUpdates, outputStream);
 		}
 	}
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkPushConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkPushConnection.java
index 5f8efe47c3..02960bf293 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkPushConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkPushConnection.java
@@ -137,6 +137,12 @@ class WalkPushConnection extends BaseConnection implements PushConnection {
 	public void push(final ProgressMonitor monitor,
 			final Map<String, RemoteRefUpdate> refUpdates)
 			throws TransportException {
+		push(monitor, refUpdates, null);
+	}
+
+	public void push(final ProgressMonitor monitor,
+			final Map<String, RemoteRefUpdate> refUpdates, OutputStream out)
+			throws TransportException {
 		markStartedOperation();
 		packNames = null;
 		newRefs = new TreeMap<String, Ref>(getRefsMap());