Fix that exceptions in ReceivePack cause Invalid Channel 101 exceptions

When during a PushOperation the server hits an exception different from
UnpackException the JGit server behaved wrong. That kind of exceptions
are handled so late that the connection is already released and the
information whether to talk sideband to the client is lost. In detail:
ReceivePack.receive() will call release() and that will reset the
capabilities. But later on the stack in ReceivePackServlet.doPost() it
is tried to send a response to client now with reset capabilities (no
sideband!).

Change-Id: I0a609acc6152ab43b47a93d712deb65bb1105f75
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/GitServletResponseTests.java

@@ -0,0 +1,295 @@
+/*
+ * Copyright (C) 2015, christian.Halstrick <christian.halstrick@sap.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.http.test;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.eclipse.jgit.errors.CorruptObjectException;
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
+import org.eclipse.jgit.errors.TooLargePackException;
+import org.eclipse.jgit.errors.TransportException;
+import org.eclipse.jgit.http.server.GitServlet;
+import org.eclipse.jgit.http.server.resolver.DefaultReceivePackFactory;
+import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.junit.http.HttpTestCase;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.NullProgressMonitor;
+import org.eclipse.jgit.lib.ObjectChecker;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.StoredConfig;
+import org.eclipse.jgit.revwalk.RevBlob;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.transport.PostReceiveHook;
+import org.eclipse.jgit.transport.PreReceiveHook;
+import org.eclipse.jgit.transport.ReceiveCommand;
+import org.eclipse.jgit.transport.ReceivePack;
+import org.eclipse.jgit.transport.RemoteRefUpdate;
+import org.eclipse.jgit.transport.Transport;
+import org.eclipse.jgit.transport.URIish;
+import org.eclipse.jgit.transport.resolver.RepositoryResolver;
+import org.eclipse.jgit.transport.resolver.ServiceNotAuthorizedException;
+import org.eclipse.jgit.transport.resolver.ServiceNotEnabledException;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Tests for correct responses of {@link GitServlet}. Especially error
+ * situations where the {@link GitServlet} faces exceptions during request
+ * processing are tested
+ */
+public class GitServletResponseTests extends HttpTestCase {
+	private Repository srvRepo;
+
+	private URIish srvURI;
+
+	private GitServlet gs;
+
+	private long maxPackSize = 0; // the maximum pack file size used by
+									// the server
+
+	private PostReceiveHook postHook = null;
+
+	private PreReceiveHook preHook = null;
+
+	private ObjectChecker oc = null;
+
+	/**
+	 * Setup a http server using {@link GitServlet}. Tests should be able to
+	 * configure the maximum pack file size, the object checker and custom hooks
+	 * just before they talk to the server.
+	 */
+	@Before
+	public void setUp() throws Exception {
+		super.setUp();
+
+		final TestRepository<Repository> srv = createTestRepository();
+		final String repoName = srv.getRepository().getDirectory().getName();
+
+		ServletContextHandler app = server.addContext("/git");
+		gs = new GitServlet();
+		gs.setRepositoryResolver(new RepositoryResolver<HttpServletRequest>() {
+			public Repository open(HttpServletRequest req, String name)
+					throws RepositoryNotFoundException,
+					ServiceNotEnabledException {
+				if (!name.equals(repoName))
+					throw new RepositoryNotFoundException(name);
+
+				final Repository db = srv.getRepository();
+				db.incrementOpen();
+				return db;
+			}
+		});
+		gs.setReceivePackFactory(new DefaultReceivePackFactory() {
+			public ReceivePack create(HttpServletRequest req, Repository db)
+					throws ServiceNotEnabledException,
+					ServiceNotAuthorizedException {
+				ReceivePack recv = super.create(req, db);
+				if (maxPackSize > 0)
+					recv.setMaxPackSizeLimit(maxPackSize);
+				if (postHook != null)
+					recv.setPostReceiveHook(postHook);
+				if (preHook != null)
+					recv.setPreReceiveHook(preHook);
+				if (oc != null)
+					recv.setObjectChecker(oc);
+				return recv;
+			}
+
+		});
+		app.addServlet(new ServletHolder(gs), "/*");
+
+		server.setUp();
+
+		srvRepo = srv.getRepository();
+		srvURI = toURIish(app, repoName);
+
+		StoredConfig cfg = srvRepo.getConfig();
+		cfg.setBoolean("http", null, "receivepack", true);
+		cfg.save();
+	}
+
+	/**
+	 * Configure a {@link GitServlet} that faces a {@link IllegalStateException}
+	 * during executing preReceiveHooks. This used to lead to exceptions with a
+	 * description of "invalid channel 101" on the client side. Make sure
+	 * clients receive the correct response on the correct sideband.
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void testRuntimeExceptionInPreReceiveHook() throws Exception {
+		final TestRepository client = createTestRepository();
+		final RevBlob Q_txt = client
+				.blob("some blob content to measure pack size");
+		final RevCommit Q = client.commit().add("Q", Q_txt).create();
+		final Repository clientRepo = client.getRepository();
+		final String srvBranchName = Constants.R_HEADS + "new.branch";
+		Transport t;
+
+		maxPackSize = 0;
+		postHook = null;
+		preHook = new PreReceiveHook() {
+			@Override
+			public void onPreReceive(ReceivePack rp,
+					Collection<ReceiveCommand> commands) {
+				throw new IllegalStateException();
+			}
+		};
+
+		t = Transport.open(clientRepo, srvURI);
+		try {
+			RemoteRefUpdate update = new RemoteRefUpdate(clientRepo, Q.name(),
+					srvBranchName, false, null, null);
+			try {
+				t.push(NullProgressMonitor.INSTANCE,
+						Collections.singleton(update));
+				fail("should not reach this line");
+			} catch (Exception e) {
+				assertTrue(e instanceof TransportException);
+			}
+		} finally {
+			t.close();
+		}
+	}
+
+	/**
+	 * Configure a {@link GitServlet} that faces a {@link IllegalStateException}
+	 * during executing objectChecking.
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void testObjectCheckerException() throws Exception {
+		final TestRepository client = createTestRepository();
+		final RevBlob Q_txt = client
+				.blob("some blob content to measure pack size");
+		final RevCommit Q = client.commit().add("Q", Q_txt).create();
+		final Repository clientRepo = client.getRepository();
+		final String srvBranchName = Constants.R_HEADS + "new.branch";
+		Transport t;
+
+		maxPackSize = 0;
+		postHook = null;
+		preHook = null;
+		oc = new ObjectChecker() {
+			@Override
+			public void checkCommit(byte[] raw) throws CorruptObjectException {
+				throw new IllegalStateException();
+			}
+		};
+
+		t = Transport.open(clientRepo, srvURI);
+		try {
+			RemoteRefUpdate update = new RemoteRefUpdate(clientRepo, Q.name(),
+					srvBranchName, false, null, null);
+			try {
+				t.push(NullProgressMonitor.INSTANCE,
+						Collections.singleton(update));
+				fail("should not reach this line");
+			} catch (Exception e) {
+				assertTrue(e instanceof TransportException);
+			}
+		} finally {
+			t.close();
+		}
+	}
+
+	/**
+	 * Configure a {@link GitServlet} that faces a {@link TooLargePackException}
+	 * during persisting the pack and a {@link IllegalStateException} during
+	 * executing postReceiveHooks. This used to lead to exceptions with a
+	 * description of "invalid channel 101" on the client side. Make sure
+	 * clients receive the correct response about the too large pack on the
+	 * correct sideband.
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void testUnpackErrorWithSubsequentExceptionInPostReceiveHook()
+			throws Exception {
+		final TestRepository client = createTestRepository();
+		final RevBlob Q_txt = client
+				.blob("some blob content to measure pack size");
+		final RevCommit Q = client.commit().add("Q", Q_txt).create();
+		final Repository clientRepo = client.getRepository();
+		final String srvBranchName = Constants.R_HEADS + "new.branch";
+		Transport t;
+
+		// this maxPackSize leads to an unPackError
+		maxPackSize = 400;
+		// this PostReceiveHook when called after an unsuccesfull unpack will
+		// lead to an IllegalStateException
+		postHook = new PostReceiveHook() {
+			public void onPostReceive(ReceivePack rp,
+					Collection<ReceiveCommand> commands) {
+				// the maxPackSize setting caused that the packfile couldn't be
+				// saved to disk. Calling getPackSize() now will lead to a
+				// IllegalStateException.
+				rp.getPackSize();
+			}
+		};
+
+		t = Transport.open(clientRepo, srvURI);
+		try {
+			RemoteRefUpdate update = new RemoteRefUpdate(clientRepo, Q.name(),
+					srvBranchName, false, null, null);
+			try {
+				t.push(NullProgressMonitor.INSTANCE,
+						Collections.singleton(update));
+				fail("should not reach this line");
+			} catch (Exception e) {
+				assertTrue(e instanceof TooLargePackException);
+			}
+		} finally {
+			t.close();
+		}
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseReceivePack.java

@@ -1583,7 +1583,9 @@ public abstract class BaseReceivePack {
 		pckIn = null;
 		pckOut = null;
 		refs = null;
-		enabledCapabilities = null;
+		// Keep the capabilities. If responses are sent after this release
+		// we need to remember at least whether sideband communication has to be
+		// used
 		commands = null;
 		if (timer != null) {
 			try {

org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java

@@ -240,11 +240,17 @@ public class ReceivePack extends BaseReceivePack {
 				});
 			}
 
+			if (unpackError != null) {
+				// we already know which exception to throw. Ignore
+				// potential additional exceptions raised in postReceiveHooks
+				try {
 					postReceive.onPostReceive(this, filterCommands(Result.OK));
-
+				} catch (Throwable e) {
-			if (unpackError != null)
+				}
 				throw new UnpackException(unpackError);
 			}
+			postReceive.onPostReceive(this, filterCommands(Result.OK));
+		}
 	}
 
 	@Override