Improve exception thrown when pull can't find advertised ref

- throw an API exception instead of an internal exception to allow
applications to handle this problem
- improve error message to give hints about possible root causes

Bug: 464660
Change-Id: Ib7d18bb2eeeac0fc218daea375b290ea5034bda1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties

@@ -181,7 +181,7 @@ corruptObjectTruncatedInObjectId=truncated in object id
 couldNotCheckOutBecauseOfConflicts=Could not check out because of conflicts
 couldNotDeleteLockFileShouldNotHappen=Could not delete lock file. Should not happen
 couldNotDeleteTemporaryIndexFileShouldNotHappen=Could not delete temporary index file. Should not happen
-couldNotGetAdvertisedRef=Could not get advertised Ref for branch {0}
+couldNotGetAdvertisedRef=Remote {0} did not advertise Ref for branch {1}. This Ref may not exist in the remote or may be hidden by permission settings.
 couldNotGetRepoStatistics=Could not get repository statistics
 couldNotLockHEAD=Could not lock HEAD
 couldNotReadIndexInOneGo=Could not read index in one go, only {0} out of {1} read

org.eclipse.jgit/src/org/eclipse/jgit/api/PullCommand.java

@@ -54,6 +54,7 @@ import org.eclipse.jgit.api.errors.InvalidConfigurationException;
 import org.eclipse.jgit.api.errors.InvalidRemoteException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.api.errors.NoHeadException;
+import org.eclipse.jgit.api.errors.RefNotAdvertisedException;
 import org.eclipse.jgit.api.errors.RefNotFoundException;
 import org.eclipse.jgit.api.errors.WrongRepositoryStateException;
 import org.eclipse.jgit.internal.JGitText;
@@ -171,6 +172,7 @@ public class PullCommand extends TransportCommand<PullCommand, PullResult> {
 	 * @throws InvalidRemoteException
 	 * @throws CanceledException
 	 * @throws RefNotFoundException
+	 * @throws RefNotAdvertisedException
 	 * @throws NoHeadException
 	 * @throws org.eclipse.jgit.api.errors.TransportException
 	 * @throws GitAPIException
@@ -178,7 +180,7 @@ public class PullCommand extends TransportCommand<PullCommand, PullResult> {
 	public PullResult call() throws GitAPIException,
 			WrongRepositoryStateException, InvalidConfigurationException,
 			DetachedHeadException, InvalidRemoteException, CanceledException,
-			RefNotFoundException, NoHeadException,
+			RefNotFoundException, RefNotAdvertisedException, NoHeadException,
 			org.eclipse.jgit.api.errors.TransportException {
 		checkCallable();
 
@@ -284,11 +286,13 @@ public class PullCommand extends TransportCommand<PullCommand, PullResult> {
 					r = fetchRes.getAdvertisedRef(Constants.R_HEADS
 							+ remoteBranchName);
 			}
-			if (r == null)
-				throw new JGitInternalException(MessageFormat.format(JGitText
-						.get().couldNotGetAdvertisedRef, remoteBranchName));
-			else
+			if (r == null) {
+				throw new RefNotAdvertisedException(MessageFormat.format(
+						JGitText.get().couldNotGetAdvertisedRef, remote,
+						remoteBranchName));
+			} else {
 				commitToMerge = r.getObjectId();
+			}
 		} else {
 			try {
 				commitToMerge = repo.resolve(remoteBranchName);

org.eclipse.jgit/src/org/eclipse/jgit/api/errors/RefNotAdvertisedException.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2015,Matthias Sohn <matthias.sohn@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.api.errors;
+
+/**
+ * Thrown when a ref is not found in advertised refs
+ *
+ * @since 4.0
+ */
+public class RefNotAdvertisedException extends GitAPIException {
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * @param message
+	 */
+	public RefNotAdvertisedException(String message) {
+		super(message);
+	}
+}