Ensure all smart HTTP errors are sent to clients

Error messages are typically short, below the 32 KiB in-memory buffer
size of the SmartOutputStream. When an error is queued up for sending
to a client and an exception is thrown up into the servlet handler we
discarded the message and sent nothing to the client, as the messages
were stuck inside of the SmartOutputStream buffer.

Hoist the creation of the output stream above the invocation of try
block of the service, and use close() in the few catch blocks that
assume there are buffered messages ready for transmission. This will
ensure errors from unpacking a stream in ReceivePack are sent off to
a client correctly, as previously these were causing no status report
to arrive at the client side as the data was stuck in the buffer.

Change-Id: I5534b560697731121f48979ae077aa7c95b8e39c

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/ReceivePackServlet.java

@@ -158,17 +158,18 @@ class ReceivePackServlet extends HttpServlet {
 			return;
 		}
 
+		SmartOutputStream out = new SmartOutputStream(req, rsp) {
+			@Override
+			public void flush() throws IOException {
+				doFlush();
+			}
+		};
+
 		ReceivePack rp = (ReceivePack) req.getAttribute(ATTRIBUTE_HANDLER);
 		try {
 			rp.setBiDirectionalPipe(false);
 			rsp.setContentType(RECEIVE_PACK_RESULT_TYPE);
 
-			final SmartOutputStream out = new SmartOutputStream(req, rsp) {
-				@Override
-				public void flush() throws IOException {
-					doFlush();
-				}
-			};
 			rp.receive(getInputStream(req), out, null);
 			out.close();
 		} catch (UnpackException e) {
@@ -176,8 +177,9 @@ class ReceivePackServlet extends HttpServlet {
 			getServletContext().log(
 					HttpServerText.get().internalErrorDuringReceivePack,
 					e.getCause());
+			out.close();
 
-		} catch (IOException e) {
+		} catch (Throwable e) {
 			getServletContext().log(HttpServerText.get().internalErrorDuringReceivePack, e);
 			if (!rsp.isCommitted()) {
 				rsp.reset();

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/UploadPackServlet.java

@@ -160,22 +160,25 @@ class UploadPackServlet extends HttpServlet {
 			return;
 		}
 
+		SmartOutputStream out = new SmartOutputStream(req, rsp) {
+			@Override
+			public void flush() throws IOException {
+				doFlush();
+			}
+		};
+
 		UploadPack up = (UploadPack) req.getAttribute(ATTRIBUTE_HANDLER);
 		try {
 			up.setBiDirectionalPipe(false);
 			rsp.setContentType(UPLOAD_PACK_RESULT_TYPE);
 
-			final SmartOutputStream out = new SmartOutputStream(req, rsp) {
-				@Override
-				public void flush() throws IOException {
-					doFlush();
-				}
-			};
 			up.upload(getInputStream(req), out, null);
 			out.close();
 
 		} catch (UploadPackMayNotContinueException e) {
-			if (!e.isOutput() && !rsp.isCommitted()) {
+			if (e.isOutput()) {
+				out.close();
+			} else if (!rsp.isCommitted()) {
 				rsp.reset();
 				sendError(req, rsp, SC_FORBIDDEN, e.getMessage());
 			}
@@ -186,8 +189,9 @@ class UploadPackServlet extends HttpServlet {
 			getServletContext().log(
 					HttpServerText.get().internalErrorDuringUploadPack,
 					e.getCause());
+			out.close();
 
-		} catch (IOException e) {
+		} catch (Throwable e) {
 			getServletContext().log(HttpServerText.get().internalErrorDuringUploadPack, e);
 			if (!rsp.isCommitted()) {
 				rsp.reset();

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

@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) 2010, Google Inc.
+ * 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.assertEquals;
+import static org.junit.Assert.assertSame;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.eclipse.jgit.JGitText;
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
+import org.eclipse.jgit.http.server.GitServlet;
+import org.eclipse.jgit.http.server.GitSmartHttpTools;
+import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.junit.http.HttpTestCase;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevBlob;
+import org.eclipse.jgit.storage.file.FileBasedConfig;
+import org.eclipse.jgit.storage.file.FileRepository;
+import org.eclipse.jgit.transport.PacketLineIn;
+import org.eclipse.jgit.transport.PacketLineOut;
+import org.eclipse.jgit.transport.URIish;
+import org.eclipse.jgit.transport.resolver.RepositoryResolver;
+import org.eclipse.jgit.transport.resolver.ServiceNotEnabledException;
+import org.eclipse.jgit.util.NB;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ProtocolErrorTest extends HttpTestCase {
+	private FileRepository remoteRepository;
+
+	private URIish remoteURI;
+
+	private RevBlob a_blob;
+
+	@Before
+	public void setUp() throws Exception {
+		super.setUp();
+
+		final TestRepository<FileRepository> src = createTestRepository();
+		final String srcName = src.getRepository().getDirectory().getName();
+
+		ServletContextHandler app = server.addContext("/git");
+		GitServlet gs = new GitServlet();
+		gs.setRepositoryResolver(new RepositoryResolver<HttpServletRequest>() {
+			public Repository open(HttpServletRequest req, String name)
+					throws RepositoryNotFoundException,
+					ServiceNotEnabledException {
+				if (!name.equals(srcName))
+					throw new RepositoryNotFoundException(name);
+
+				final Repository db = src.getRepository();
+				db.incrementOpen();
+				return db;
+			}
+		});
+		app.addServlet(new ServletHolder(gs), "/*");
+
+		server.setUp();
+
+		remoteRepository = src.getRepository();
+		remoteURI = toURIish(app, srcName);
+
+		FileBasedConfig cfg = remoteRepository.getConfig();
+		cfg.setBoolean("http", null, "receivepack", true);
+		cfg.save();
+
+		a_blob = src.blob("a");
+	}
+
+	@Test
+	public void testPush_UnpackError_TruncatedPack() throws Exception {
+		StringBuilder sb = new StringBuilder();
+		sb.append(ObjectId.zeroId().name());
+		sb.append(' ');
+		sb.append(a_blob.name());
+		sb.append(' ');
+		sb.append("refs/objects/A");
+		sb.append('\0');
+		sb.append("report-status");
+
+		ByteArrayOutputStream reqbuf = new ByteArrayOutputStream();
+		PacketLineOut reqpck = new PacketLineOut(reqbuf);
+		reqpck.writeString(sb.toString());
+		reqpck.end();
+
+		packHeader(reqbuf, 1);
+
+		byte[] reqbin = reqbuf.toByteArray();
+
+		URL u = new URL(remoteURI.toString() + "/git-receive-pack");
+		HttpURLConnection c = (HttpURLConnection) u.openConnection();
+		try {
+			c.setRequestMethod("POST");
+			c.setDoOutput(true);
+			c.setRequestProperty("Content-Type",
+					GitSmartHttpTools.RECEIVE_PACK_REQUEST_TYPE);
+			c.setFixedLengthStreamingMode(reqbin.length);
+			OutputStream out = c.getOutputStream();
+			try {
+				out.write(reqbin);
+			} finally {
+				out.close();
+			}
+
+			assertEquals(200, c.getResponseCode());
+			assertEquals(GitSmartHttpTools.RECEIVE_PACK_RESULT_TYPE,
+					c.getContentType());
+
+			InputStream rawin = c.getInputStream();
+			try {
+				PacketLineIn pckin = new PacketLineIn(rawin);
+				assertEquals("unpack error "
+						+ JGitText.get().packfileIsTruncated,
+						pckin.readString());
+				assertEquals("ng refs/objects/A n/a (unpacker error)",
+						pckin.readString());
+				assertSame(PacketLineIn.END, pckin.readString());
+			} finally {
+				rawin.close();
+			}
+		} finally {
+			c.disconnect();
+		}
+	}
+
+	private void packHeader(ByteArrayOutputStream tinyPack, int cnt)
+			throws IOException {
+		final byte[] hdr = new byte[8];
+		NB.encodeInt32(hdr, 0, 2);
+		NB.encodeInt32(hdr, 4, cnt);
+
+		tinyPack.write(Constants.PACK_SIGNATURE);
+		tinyPack.write(hdr, 0, 8);
+	}
+}