Report PackProtocolExceptions to client during receive-pack

We have done this since forever with the "wanted old new ref" error,
so let's do it for other such errors thrown in the same block as well.

Change-Id: Ib3b1c7f05e31a5b3e40e85eb07b16736920a033b

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

@@ -76,6 +76,7 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import org.eclipse.jgit.errors.CorruptObjectException;
+import org.eclipse.jgit.errors.PackProtocolException;
 import org.eclipse.jgit.errors.UnpackException;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.transport.InternalHttpServerGlue;
@@ -200,7 +201,7 @@ class ReceivePackServlet extends HttpServlet {
 			consumeRequestBody(req);
 			out.close();
 
-		} catch (UnpackException e) {
+		} catch (UnpackException | PackProtocolException e) {
 			// This should be already reported to the client.
 			log(rp.getRepository(), e.getCause());
 			consumeRequestBody(req);

org.eclipse.jgit/src/org/eclipse/jgit/errors/PackProtocolException.java

@@ -60,7 +60,7 @@ public class PackProtocolException extends TransportException {
 	 * @param uri
 	 *            URI used for transport
 	 * @param s
-	 *            message
+	 *            message, which may be shown to an end-user.
 	 */
 	public PackProtocolException(final URIish uri, final String s) {
 		super(uri + ": " + s); //$NON-NLS-1$
@@ -73,7 +73,7 @@ public class PackProtocolException extends TransportException {
 	 * @param uri
 	 *            URI used for transport
 	 * @param s
-	 *            message
+	 *            message, which may be shown to an end-user.
 	 * @param cause
 	 *            root cause exception
 	 */
@@ -86,7 +86,7 @@ public class PackProtocolException extends TransportException {
 	 * Constructs an PackProtocolException with the specified detail message.
 	 *
 	 * @param s
-	 *            message
+	 *            message, which may be shown to an end-user.
 	 */
 	public PackProtocolException(final String s) {
 		super(s);
@@ -96,7 +96,7 @@ public class PackProtocolException extends TransportException {
 	 * Constructs an PackProtocolException with the specified detail message.
 	 *
 	 * @param s
-	 *            message
+	 *            message, which may be shown to an end-user.
 	 * @param cause
 	 *            root cause exception
 	 */

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

@@ -1065,6 +1065,7 @@ public abstract class BaseReceivePack {
 	protected void recvCommands() throws IOException {
 		PushCertificateParser certParser = getPushCertificateParser();
 		FirstLine firstLine = null;
+		try {
 			for (;;) {
 				String line;
 				try {
@@ -1116,6 +1117,10 @@ public abstract class BaseReceivePack {
 					certParser.addCommand(cmd);
 				}
 			}
+		} catch (PackProtocolException e) {
+			sendError(e.getMessage());
+			throw e;
+		}
 	}
 
 	static ReceiveCommand parseCommand(String line) throws PackProtocolException {