diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
index af8d56498..fca9018db 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
@@ -390,6 +390,7 @@ invalidPathPeriodAtEndWindows=Invalid path (period at end is ignored by Windows)
 invalidPathSpaceAtEndWindows=Invalid path (space at end is ignored by Windows): {0}
 invalidPathReservedOnWindows=Invalid path (''{0}'' is reserved on Windows): {1}
 invalidRedirectLocation=Invalid redirect location {0} -> {1}
+invalidRefAdvertisementLine=Invalid ref advertisement line: ''{1}''
 invalidReflogRevision=Invalid reflog revision: {0}
 invalidRefName=Invalid ref name: {0}
 invalidReftableBlock=Invalid reftable block
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
index 99445b2f4..a24cff1e4 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
@@ -451,6 +451,7 @@ public static JGitText get() {
 	/***/ public String invalidPathSpaceAtEndWindows;
 	/***/ public String invalidPathReservedOnWindows;
 	/***/ public String invalidRedirectLocation;
+	/***/ public String invalidRefAdvertisementLine;
 	/***/ public String invalidReflogRevision;
 	/***/ public String invalidRefName;
 	/***/ public String invalidReftableBlock;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackConnection.java
index 38eae1cd4..fcf78ac7b 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackConnection.java
@@ -57,6 +57,7 @@
 import java.util.LinkedHashMap;
 import java.util.Set;
 
+import org.eclipse.jgit.errors.InvalidObjectIdException;
 import org.eclipse.jgit.errors.NoRemoteRepositoryException;
 import org.eclipse.jgit.errors.PackProtocolException;
 import org.eclipse.jgit.errors.RemoteRepositoryException;
@@ -222,6 +223,10 @@ private void readAdvertisedRefsImpl() throws IOException {
 				}
 			}
 
+			// Expecting to get a line in the form "sha1 refname"
+			if (line.length() < 41 || line.charAt(40) != ' ') {
+				throw invalidRefAdvertisementLine(line);
+			}
 			String name = line.substring(41, line.length());
 			if (avail.isEmpty() && name.equals("capabilities^{}")) { //$NON-NLS-1$
 				// special line from git-receive-pack to show
@@ -229,7 +234,12 @@ private void readAdvertisedRefsImpl() throws IOException {
 				continue;
 			}
 
-			final ObjectId id = ObjectId.fromString(line.substring(0, 40));
+			final ObjectId id;
+			try {
+				id  = ObjectId.fromString(line.substring(0, 40));
+			} catch (InvalidObjectIdException e) {
+				throw invalidRefAdvertisementLine(line);
+			}
 			if (name.equals(".have")) { //$NON-NLS-1$
 				additionalHaves.add(id);
 			} else if (name.endsWith("^{}")) { //$NON-NLS-1$
@@ -318,6 +328,10 @@ private PackProtocolException duplicateAdvertisement(String name) {
 		return new PackProtocolException(uri, MessageFormat.format(JGitText.get().duplicateAdvertisementsOf, name));
 	}
 
+	private PackProtocolException invalidRefAdvertisementLine(String line) {
+		return new PackProtocolException(uri, MessageFormat.format(JGitText.get().invalidRefAdvertisementLine, line));
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public void close() {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
index 4f2ea64e1..d0db9f0e9 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
@@ -134,12 +134,31 @@ static ProtocolVersion parse(@Nullable String name) {
 	final @Nullable ProtocolVersion protocolVersion;
 	final String[] hideRefs;
 
-	TransferConfig(Repository db) {
+	/**
+	 * Create a configuration honoring the repository's settings.
+	 *
+	 * @param db
+	 *            the repository to read settings from. The repository is not
+	 *            retained by the new configuration, instead its settings are
+	 *            copied during the constructor.
+	 * @since 5.1.4
+	 */
+	public TransferConfig(Repository db) {
 		this(db.getConfig());
 	}
 
+	/**
+	 * Create a configuration honoring settings in a
+	 * {@link org.eclipse.jgit.lib.Config}.
+	 *
+	 * @param rc
+	 *            the source to read settings from. The source is not retained
+	 *            by the new configuration, instead its settings are copied
+	 *            during the constructor.
+	 * @since 5.1.4
+	 */
 	@SuppressWarnings("nls")
-	TransferConfig(Config rc) {
+	public TransferConfig(Config rc) {
 		boolean fsck = rc.getBoolean("transfer", "fsckobjects", false);
 		fetchFsck = rc.getBoolean("fetch", "fsckobjects", fsck);
 		receiveFsck = rc.getBoolean("receive", "fsckobjects", fsck);