Merge branch 'master' into stable-5.10

* master:
  Prepare 5.3.10-SNAPSHOT builds
  JGit v5.3.9.202012012026-r
  Prepare 5.1.16-SNAPSHOT builds
  JGit v5.1.15.202012011955-r
  Fix PackInvalidException when fetch and repack run concurrently
  Upgrade maven-pmd-plugin to 3.14.0
  Update Orbit to R20201130205003 for 2020-12
  Use new protocol version constants
  PacketLineInTest: test for END and DELIM being distinguishable
  Add constants for parsing git wire protocol version
  Ignore missing javadoc tags in test bundles
  Bazel: Allow to build and run the tests with JDK 15
  [releng] japicmp: update last release version
  Add support for reading symrefs from pack capabilities

Change-Id: I5afbbb912f502991f0cf9c2501b024f5f00144ba
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
diff --git a/.bazelversion b/.bazelversion
index 1545d96..8faff82 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-3.5.0
+4.0.0rc2
diff --git a/WORKSPACE b/WORKSPACE
index 7651cba..ad04d14 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -27,6 +27,34 @@
     "maven_jar",
 )
 
+http_archive(
+    name = "openjdk15_linux_archive",
+    build_file_content = """
+java_runtime(name = 'runtime', srcs =  glob(['**']), visibility = ['//visibility:public'])
+exports_files(["WORKSPACE"], visibility = ["//visibility:public"])
+""",
+    sha256 = "0a38f1138c15a4f243b75eb82f8ef40855afcc402e3c2a6de97ce8235011b1ad",
+    strip_prefix = "zulu15.27.17-ca-jdk15.0.0-linux_x64",
+    urls = [
+        "https://mirror.bazel.build/cdn.azul.com/zulu/bin/zulu15.27.17-ca-jdk15.0.0-linux_x64.tar.gz",
+        "https://cdn.azul.com/zulu/bin/zulu15.27.17-ca-jdk15.0.0-linux_x64.tar.gz",
+    ],
+)
+
+http_archive(
+    name = "openjdk15_darwin_archive",
+    build_file_content = """
+java_runtime(name = 'runtime', srcs =  glob(['**']), visibility = ['//visibility:public'])
+exports_files(["WORKSPACE"], visibility = ["//visibility:public"])
+""",
+    sha256 = "f80b2e0512d9d8a92be24497334c974bfecc8c898fc215ce0e76594f00437482",
+    strip_prefix = "zulu15.27.17-ca-jdk15.0.0-macosx_x64",
+    urls = [
+        "https://mirror.bazel.build/cdn.azul.com/zulu/bin/zulu15.27.17-ca-jdk15.0.0-macosx_x64.tar.gz",
+        "https://cdn.azul.com/zulu/bin/zulu15.27.17-ca-jdk15.0.0-macosx_x64.tar.gz",
+    ],
+)
+
 JMH_VERS = "1.21"
 
 maven_jar(
diff --git a/org.eclipse.jgit.ant.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.ant.test/.settings/org.eclipse.jdt.core.prefs
index 3dd5840..b853c6a 100644
--- a/org.eclipse.jgit.ant.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.ant.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.gpg.bc.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.gpg.bc.test/.settings/org.eclipse.jdt.core.prefs
index 822846c..cba893f 100644
--- a/org.eclipse.jgit.gpg.bc.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.gpg.bc.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.http.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.http.test/.settings/org.eclipse.jdt.core.prefs
index 3dd5840..b853c6a 100644
--- a/org.eclipse.jgit.http.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.http.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HttpClientTests.java b/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HttpClientTests.java
index 9665776..26a453b 100644
--- a/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HttpClientTests.java
+++ b/org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HttpClientTests.java
@@ -38,6 +38,7 @@
 import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.junit.http.AccessEvent;
 import org.eclipse.jgit.junit.http.AppServer;
+import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -49,6 +50,7 @@
 import org.eclipse.jgit.transport.PacketLineIn;
 import org.eclipse.jgit.transport.PacketLineOut;
 import org.eclipse.jgit.transport.Transport;
+import org.eclipse.jgit.transport.TransferConfig;
 import org.eclipse.jgit.transport.URIish;
 import org.eclipse.jgit.transport.UsernamePasswordCredentialsProvider;
 import org.eclipse.jgit.transport.http.HttpConnection;
@@ -342,8 +344,10 @@ public void testHttpClientWantsV2ButServerNotConfigured() throws Exception {
 
 	@Test
 	public void testV2HttpFirstResponse() throws Exception {
-		remoteRepository.getRepository().getConfig().setInt(
-				"protocol", null, "version", 2);
+		remoteRepository.getRepository().getConfig().setString(
+				ConfigConstants.CONFIG_PROTOCOL_SECTION, null,
+				ConfigConstants.CONFIG_KEY_VERSION,
+				TransferConfig.ProtocolVersion.V2.version());
 
 		String url = smartAuthNoneURI.toString() + "/info/refs?service=git-upload-pack";
 		HttpConnection c = HttpTransport.getConnectionFactory()
@@ -364,8 +368,10 @@ public void testV2HttpFirstResponse() throws Exception {
 
 	@Test
 	public void testV2HttpSubsequentResponse() throws Exception {
-		remoteRepository.getRepository().getConfig().setInt(
-				"protocol", null, "version", 2);
+		remoteRepository.getRepository().getConfig().setString(
+				ConfigConstants.CONFIG_PROTOCOL_SECTION, null,
+				ConfigConstants.CONFIG_KEY_VERSION,
+				TransferConfig.ProtocolVersion.V2.version());
 
 		String url = smartAuthNoneURI.toString() + "/git-upload-pack";
 		HttpConnection c = HttpTransport.getConnectionFactory()
diff --git a/org.eclipse.jgit.lfs.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.lfs.test/.settings/org.eclipse.jdt.core.prefs
index 3dd5840..b853c6a 100644
--- a/org.eclipse.jgit.lfs.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.lfs.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.target
index 931e196..d7e1585 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.10" sequenceNumber="1605866255">
+<target name="jgit-4.10" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.tpd
index b87917b..d84f801 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.10.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.10" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2018-12/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.target
index 8090999..42ef49c 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.11" sequenceNumber="1605866333">
+<target name="jgit-4.11" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.tpd
index 844a1d7..df221e6 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.11.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.11" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2019-03/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.target
index 69eb639..17634cf 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.12" sequenceNumber="1605866333">
+<target name="jgit-4.12" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.tpd
index afbf79d..56fd714 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.12.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.12" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2019-06/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.target
index fdbed2d..04b536e 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.13" sequenceNumber="1605866333">
+<target name="jgit-4.13" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.tpd
index d83e338..46069c3 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.13.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.13" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2019-09/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.target
index c2ef9d2..c1722ff 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.14" sequenceNumber="1605866331">
+<target name="jgit-4.14" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.tpd
index f357ccd..f517ab2 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.14.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.14" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2019-12/201912181000/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.target
index 4034d2a..7f5f5a1 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.15" sequenceNumber="1605866331">
+<target name="jgit-4.15" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.tpd
index 881fe37..1e4a0ee 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.15.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.15" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2020-03/202003181000/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.target
index 34d872c..bba090a 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.16" sequenceNumber="1605866333">
+<target name="jgit-4.16" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.tpd
index 9a07597..2435c48 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.16.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.16" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2020-06/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.target
index 3384c23..d7c1728 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.17" sequenceNumber="1605866541">
+<target name="jgit-4.17" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.tpd
index ce79cf4..4327415 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.17.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.17" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2020-09/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.target
index 5eeab95..913009d 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.18-staging" sequenceNumber="1605866541">
+<target name="jgit-4.18-staging" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.tpd
index 0669490..d8e3445 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.18-staging.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.18-staging" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/staging/2020-12/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.target
index a66fcc0..061dcf2 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.6" sequenceNumber="1605866347">
+<target name="jgit-4.6" sequenceNumber="1606854620">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.tpd
index aa58b68..c7fbf02 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.6.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.6" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/neon/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.target
index 4b5410a..b96c54d 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.7" sequenceNumber="1605866338">
+<target name="jgit-4.7" sequenceNumber="1606854608">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.tpd
index e2264e0..585e04b 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.7.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.7" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/oxygen/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.target
index d776427..3ddc0bc 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.8" sequenceNumber="1605866333">
+<target name="jgit-4.8" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.tpd
index c92ce53..694fc67 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.8.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.8" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/photon/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.target b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.target
index 56002b7..f119fc1 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.target
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.target
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="jgit-4.9" sequenceNumber="1605866333">
+<target name="jgit-4.9" sequenceNumber="1606854603">
   <locations>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.jetty.client" version="9.4.30.v20200611"/>
@@ -84,7 +84,7 @@
       <unit id="org.slf4j.binding.log4j12.source" version="1.7.30.v20201108-2042"/>
       <unit id="org.tukaani.xz" version="1.8.0.v20180207-1613"/>
       <unit id="org.tukaani.xz.source" version="1.8.0.v20180207-1613"/>
-      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository"/>
+      <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository"/>
     </location>
     <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
       <unit id="org.eclipse.osgi" version="0.0.0"/>
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.tpd
index 06ccecb..ae5390c 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/jgit-4.9.tpd
@@ -1,7 +1,7 @@
 target "jgit-4.9" with source configurePhase
 
 include "projects/jetty-9.4.x.tpd"
-include "orbit/S20201118210000.tpd"
+include "orbit/R20201130205003-2020-12.tpd"
 
 location "https://download.eclipse.org/releases/2018-09/" {
 	org.eclipse.osgi lazy
diff --git a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/orbit/S20201118210000.tpd b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/orbit/R20201130205003-2020-12.tpd
similarity index 97%
rename from org.eclipse.jgit.packaging/org.eclipse.jgit.target/orbit/S20201118210000.tpd
rename to org.eclipse.jgit.packaging/org.eclipse.jgit.target/orbit/R20201130205003-2020-12.tpd
index a00a5e7..08a0846 100644
--- a/org.eclipse.jgit.packaging/org.eclipse.jgit.target/orbit/S20201118210000.tpd
+++ b/org.eclipse.jgit.packaging/org.eclipse.jgit.target/orbit/R20201130205003-2020-12.tpd
@@ -1,7 +1,7 @@
-target "S20201118210000" with source configurePhase
+target "R20201130205003-2020-12" with source configurePhase
 // see https://download.eclipse.org/tools/orbit/downloads/
 
-location "https://download.eclipse.org/tools/orbit/downloads/drops/S20201118210000/repository" {
+location "https://download.eclipse.org/tools/orbit/downloads/drops/R20201130205003/repository" {
 	com.google.gson [2.8.2.v20180104-1110,2.8.2.v20180104-1110]
 	com.google.gson.source [2.8.2.v20180104-1110,2.8.2.v20180104-1110]
 	com.jcraft.jsch [0.1.55.v20190404-1902,0.1.55.v20190404-1902]
diff --git a/org.eclipse.jgit.pgm.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.pgm.test/.settings/org.eclipse.jdt.core.prefs
index 3dd5840..b853c6a 100644
--- a/org.eclipse.jgit.pgm.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.pgm.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsRemoteTest.java b/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsRemoteTest.java
index 4ecaeb6..46eec74 100644
--- a/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsRemoteTest.java
+++ b/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsRemoteTest.java
@@ -33,7 +33,7 @@ public void setUp() throws Exception {
 		git.add().addFilepattern("Test.txt").call();
 		git.commit().setMessage("Initial commit").call();
 
-		// create a master branch and switch to it
+		// create a test branch and switch to it
 		git.branchCreate().setName("test").call();
 		RefUpdate rup = db.updateRef(Constants.HEAD);
 		rup.link("refs/heads/test");
@@ -104,4 +104,22 @@ public void testLsRemoteHeadsTags() throws Exception {
 				"" }, result.toArray());
 	}
 
+	@Test
+	public void testLsRemoteSymRefs() throws Exception {
+		final List<String> result = CLIGitCommand.execute(
+				"git ls-remote --symref " + shellQuote(db.getDirectory()), db);
+		assertArrayEquals(new String[] {
+				"ref: refs/heads/test	HEAD",
+				"d0b1ef2b3dea02bb2ca824445c04e6def012c32c	HEAD",
+				"d0b1ef2b3dea02bb2ca824445c04e6def012c32c	refs/heads/master",
+				"d0b1ef2b3dea02bb2ca824445c04e6def012c32c	refs/heads/test",
+				"efc02078d83a5226986ae917323acec7e1e8b7cb	refs/tags/tag1",
+				"d0b1ef2b3dea02bb2ca824445c04e6def012c32c	refs/tags/tag1^{}",
+				"4e4b837e0fd4ba83c003678b03592dc1509a4115	refs/tags/tag2",
+				"d0b1ef2b3dea02bb2ca824445c04e6def012c32c	refs/tags/tag2^{}",
+				"489384bf8ace47522fe32093d2ceb85b65a6cbb1	refs/tags/tag3",
+				"d0b1ef2b3dea02bb2ca824445c04e6def012c32c	refs/tags/tag3^{}",
+				"" }, result.toArray());
+	}
+
 }
diff --git a/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties b/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
index c116437..6112a27 100644
--- a/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
+++ b/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
@@ -256,6 +256,7 @@
 usage_LsRemote=List references in a remote repository
 usage_lsRemoteHeads=Show only refs starting with refs/heads
 usage_lsRemoteTags=Show only refs starting with refs/tags
+usage_lsRemoteSymref=In addition to the object pointed at, show the underlying ref pointed at when showing a symbolic ref.
 usage_LsTree=List the contents of a tree object
 usage_MakeCacheTree=Show the current cache tree structure
 usage_Match=Only consider tags matching the given glob(7) pattern or patterns, excluding the "refs/tags/" prefix.
diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsRemote.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsRemote.java
index 36812c0..055b48a 100644
--- a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsRemote.java
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsRemote.java
@@ -34,6 +34,9 @@ class LsRemote extends TextBuiltin {
 	@Option(name = "--timeout", metaVar = "metaVar_service", usage = "usage_abortConnectionIfNoActivity")
 	int timeout = -1;
 
+	@Option(name = "--symref", usage = "usage_lsRemoteSymref")
+	private boolean symref;
+
 	@Argument(index = 0, metaVar = "metaVar_uriish", required = true)
 	private String remote;
 
@@ -47,6 +50,9 @@ protected void run() {
 		try {
 			refs.addAll(command.call());
 			for (Ref r : refs) {
+				if (symref && r.isSymbolic()) {
+					show(r.getTarget(), r.getName());
+				}
 				show(r.getObjectId(), r.getName());
 				if (r.getPeeledObjectId() != null) {
 					show(r.getPeeledObjectId(), r.getName() + "^{}"); //$NON-NLS-1$
@@ -70,4 +76,13 @@ private void show(AnyObjectId id, String name)
 		outw.print(name);
 		outw.println();
 	}
+
+	private void show(Ref ref, String name)
+			throws IOException {
+		outw.print("ref: ");
+		outw.print(ref.getName());
+		outw.print('\t');
+		outw.print(name);
+		outw.println();
+	}
 }
diff --git a/org.eclipse.jgit.ssh.apache.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.ssh.apache.test/.settings/org.eclipse.jdt.core.prefs
index 822846c..cba893f 100644
--- a/org.eclipse.jgit.ssh.apache.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.ssh.apache.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.ssh.jsch.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.ssh.jsch.test/.settings/org.eclipse.jdt.core.prefs
index 2bc2cf3..c16c986 100644
--- a/org.eclipse.jgit.ssh.jsch.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.ssh.jsch.test/.settings/org.eclipse.jdt.core.prefs
@@ -52,8 +52,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.test/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.jgit.test/.settings/org.eclipse.jdt.core.prefs
index 3dd5840..b853c6a 100644
--- a/org.eclipse.jgit.test/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.jgit.test/.settings/org.eclipse.jdt.core.prefs
@@ -51,8 +51,8 @@
 org.eclipse.jdt.core.compiler.problem.missingJavadocComments=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=protected
-org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=return_tag
-org.eclipse.jdt.core.compiler.problem.missingJavadocTags=error
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=no_tag
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=ignore
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
 org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=private
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
index b737bbe..de25870 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
@@ -92,7 +92,6 @@ public void testCloneRepository() throws IOException,
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		ObjectId id = git2.getRepository().resolve("tag-for-blob");
 		assertNotNull(id);
 		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/test");
@@ -277,8 +276,7 @@ public void testCloneRepositoryWithBranch() throws IOException,
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
 
-		assertNotNull(git2);
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/master");
+		assertEquals("refs/heads/master", git2.getRepository().getFullBranch());
 		assertEquals(
 				"refs/heads/master, refs/remotes/origin/master, refs/remotes/origin/test",
 				allRefNames(git2.branchList().setListMode(ListMode.ALL).call()));
@@ -293,7 +291,6 @@ public void testCloneRepositoryWithBranch() throws IOException,
 		git2 = command.call();
 		addRepoToClose(git2.getRepository());
 
-		assertNotNull(git2);
 		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/master");
 		assertEquals("refs/remotes/origin/master, refs/remotes/origin/test",
 				allRefNames(git2.branchList().setListMode(ListMode.ALL).call()));
@@ -308,8 +305,7 @@ public void testCloneRepositoryWithBranch() throws IOException,
 		git2 = command.call();
 		addRepoToClose(git2.getRepository());
 
-		assertNotNull(git2);
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/master");
+		assertEquals("refs/heads/master", git2.getRepository().getFullBranch());
 		assertEquals("refs/heads/master, refs/heads/test", allRefNames(git2
 				.branchList().setListMode(ListMode.ALL).call()));
 	}
@@ -324,7 +320,6 @@ public void testCloneRepositoryWithBranchShortName() throws Exception {
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
 
-		assertNotNull(git2);
 		assertEquals("refs/heads/test", git2.getRepository().getFullBranch());
 	}
 
@@ -338,7 +333,6 @@ public void testCloneRepositoryWithTagName() throws Exception {
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
 
-		assertNotNull(git2);
 		ObjectId taggedCommit = db.resolve("tag-initial^{commit}");
 		assertEquals(taggedCommit.name(), git2
 				.getRepository().getFullBranch());
@@ -355,10 +349,9 @@ public void testCloneRepositoryOnlyOneBranch() throws Exception {
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		assertNull(git2.getRepository().resolve("tag-for-blob"));
 		assertNotNull(git2.getRepository().resolve("tag-initial"));
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/master");
+		assertEquals("refs/heads/master", git2.getRepository().getFullBranch());
 		assertEquals("refs/remotes/origin/master", allRefNames(git2
 				.branchList().setListMode(ListMode.REMOTE).call()));
 		RemoteConfig cfg = new RemoteConfig(git2.getRepository().getConfig(),
@@ -383,10 +376,9 @@ public void testBareCloneRepositoryOnlyOneBranch() throws Exception {
 		command.setBare(true);
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		assertNull(git2.getRepository().resolve("tag-for-blob"));
 		assertNotNull(git2.getRepository().resolve("tag-initial"));
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/master");
+		assertEquals("refs/heads/master", git2.getRepository().getFullBranch());
 		assertEquals("refs/heads/master", allRefNames(git2.branchList()
 				.setListMode(ListMode.ALL).call()));
 		RemoteConfig cfg = new RemoteConfig(git2.getRepository().getConfig(),
@@ -409,11 +401,10 @@ public void testBareCloneRepositoryMirror() throws Exception {
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		assertTrue(git2.getRepository().isBare());
 		assertNotNull(git2.getRepository().resolve("tag-for-blob"));
 		assertNotNull(git2.getRepository().resolve("tag-initial"));
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/master");
+		assertEquals("refs/heads/master", git2.getRepository().getFullBranch());
 		assertEquals("refs/heads/master, refs/heads/test", allRefNames(
 				git2.branchList().setListMode(ListMode.ALL).call()));
 		assertNotNull(git2.getRepository().exactRef("refs/meta/foo/bar"));
@@ -436,7 +427,6 @@ public void testCloneRepositoryOnlyOneTag() throws Exception {
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		assertNull(git2.getRepository().resolve("tag-for-blob"));
 		assertNull(git2.getRepository().resolve("refs/heads/master"));
 		assertNotNull(git2.getRepository().resolve("tag-initial"));
@@ -464,8 +454,7 @@ public void testCloneRepositoryAllBranchesTakesPreference()
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/test");
+		assertEquals("refs/heads/test", git2.getRepository().getFullBranch());
 		// Expect both remote branches to exist; setCloneAllBranches(true)
 		// should override any setBranchesToClone().
 		assertNotNull(
@@ -492,8 +481,7 @@ public void testCloneRepositoryAllBranchesIndependent() throws Exception {
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
-		assertEquals(git2.getRepository().getFullBranch(), "refs/heads/test");
+		assertEquals("refs/heads/test", git2.getRepository().getFullBranch());
 		// Expect only the test branch; allBranches was re-set to false
 		assertNull(git2.getRepository().resolve("refs/remotes/origin/master"));
 		assertNotNull(git2.getRepository().resolve("refs/remotes/origin/test"));
@@ -525,7 +513,6 @@ public void testCloneRepositoryWhenDestinationDirectoryExistsAndIsNotEmpty()
 		command.setURI(fileUri());
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		// clone again
 		command = Git.cloneRepository();
 		command.setDirectory(directory);
@@ -551,7 +538,6 @@ public void testCloneRepositoryWithMultipleHeadBranches() throws Exception {
 		clone.setURI(fileUri());
 		Git git2 = clone.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 
 		assertEquals(Constants.MASTER, git2.getRepository().getBranch());
 	}
@@ -595,7 +581,6 @@ public void testCloneRepositoryWithSubmodules() throws Exception {
 		clone.setURI(fileUri());
 		Git git2 = clone.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 
 		assertEquals(Constants.MASTER, git2.getRepository().getBranch());
 		assertTrue(new File(git2.getRepository().getWorkTree(), path
@@ -683,7 +668,6 @@ public void testCloneRepositoryWithNestedSubmodules() throws Exception {
 		clone.setURI(git.getRepository().getDirectory().toURI().toString());
 		Git git2 = clone.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 
 		assertEquals(Constants.MASTER, git2.getRepository().getBranch());
 		assertTrue(new File(git2.getRepository().getWorkTree(), path
@@ -813,7 +797,6 @@ public void testCloneNoTags() throws IOException, JGitInternalException,
 		command.setNoTags();
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		assertNotNull(git2.getRepository().resolve("refs/heads/test"));
 		assertNull(git2.getRepository().resolve("tag-initial"));
 		assertNull(git2.getRepository().resolve("tag-for-blob"));
@@ -833,13 +816,41 @@ public void testCloneFollowTags() throws IOException, JGitInternalException,
 		command.setTagOption(TagOpt.FETCH_TAGS);
 		Git git2 = command.call();
 		addRepoToClose(git2.getRepository());
-		assertNotNull(git2);
 		assertNull(git2.getRepository().resolve("refs/heads/test"));
 		assertNotNull(git2.getRepository().resolve("tag-initial"));
 		assertNotNull(git2.getRepository().resolve("tag-for-blob"));
 		assertTagOption(git2.getRepository(), TagOpt.FETCH_TAGS);
 	}
 
+	@Test
+	public void testCloneWithHeadSymRefIsMasterCopy() throws IOException, GitAPIException {
+		// create a branch with the same head as master and switch to it
+		git.checkout().setStartPoint("master").setCreateBranch(true).setName("master-copy").call();
+
+		// when we clone the HEAD symref->master-copy means we start on master-copy and not master
+		File directory = createTempDirectory("testCloneRepositorySymRef_master-copy");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+		assertEquals("refs/heads/master-copy", git2.getRepository().getFullBranch());
+	}
+
+	@Test
+	public void testCloneWithHeadSymRefIsNonMasterCopy() throws IOException, GitAPIException {
+		// create a branch with the same head as test and switch to it
+		git.checkout().setStartPoint("test").setCreateBranch(true).setName("test-copy").call();
+
+		File directory = createTempDirectory("testCloneRepositorySymRef_test-copy");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+		assertEquals("refs/heads/test-copy", git2.getRepository().getFullBranch());
+	}
+
 	private void assertTagOption(Repository repo, TagOpt expectedTagOption)
 			throws URISyntaxException {
 		RemoteConfig remoteConfig = new RemoteConfig(
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/LsRemoteCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/LsRemoteCommandTest.java
index 00f84e9..12ec2aa 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/LsRemoteCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/LsRemoteCommandTest.java
@@ -11,9 +11,11 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.util.Collection;
+import java.util.Optional;
 
 import org.eclipse.jgit.junit.RepositoryTestCase;
 import org.eclipse.jgit.lib.Constants;
@@ -34,7 +36,7 @@ public void setUp() throws Exception {
 		git.add().addFilepattern("Test.txt").call();
 		git.commit().setMessage("Initial commit").call();
 
-		// create a master branch and switch to it
+		// create a test branch and switch to it
 		git.branchCreate().setName("test").call();
 		RefUpdate rup = db.updateRef(Constants.HEAD);
 		rup.link("refs/heads/test");
@@ -104,6 +106,28 @@ public void testLsRemoteWithoutLocalRepository() throws Exception {
 		assertEquals(2, refs.size());
 	}
 
+	@Test
+	public void testLsRemoteWithSymRefs() throws Exception {
+		File directory = createTempDirectory("testRepository");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.setCloneAllBranches(true);
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+
+		LsRemoteCommand lsRemoteCommand = git2.lsRemote();
+		Collection<Ref> refs = lsRemoteCommand.call();
+		assertNotNull(refs);
+		assertEquals(6, refs.size());
+
+		Optional<Ref> headRef = refs.stream().filter(ref -> ref.getName().equals(Constants.HEAD)).findFirst();
+		assertTrue("expected a HEAD Ref", headRef.isPresent());
+		assertTrue("expected HEAD Ref to be a Symbolic", headRef.get().isSymbolic());
+		assertEquals("refs/heads/test", headRef.get().getTarget().getName());
+	}
+
 	private String fileUri() {
 		return "file://" + git.getRepository().getWorkTree().getAbsolutePath();
 	}
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/BasePackConnectionTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/BasePackConnectionTest.java
new file mode 100644
index 0000000..64b16f6
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/BasePackConnectionTest.java
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2020, Lee Worrall and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.transport;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.hasKey;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectIdRef;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.SymbolicRef;
+import org.junit.Test;
+
+public class BasePackConnectionTest {
+
+	@Test
+	public void testExtractSymRefsFromCapabilities() {
+		final Map<String, String> symRefs = BasePackConnection
+				.extractSymRefsFromCapabilities(
+						Arrays.asList("symref=HEAD:refs/heads/main",
+								"symref=refs/heads/sym:refs/heads/other"));
+
+		assertEquals(2, symRefs.size());
+		assertEquals("refs/heads/main", symRefs.get("HEAD"));
+		assertEquals("refs/heads/other", symRefs.get("refs/heads/sym"));
+	}
+
+	@Test
+	public void testUpdateWithSymRefsAdds() {
+		final Ref mainRef = new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE,
+				"refs/heads/main", ObjectId.fromString(
+						"0000000000000000000000000000000000000001"));
+
+		final Map<String, Ref> refMap = new HashMap<>();
+		refMap.put(mainRef.getName(), mainRef);
+		refMap.put("refs/heads/other",
+				new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "refs/heads/other",
+						ObjectId.fromString(
+								"0000000000000000000000000000000000000002")));
+
+		final Map<String, String> symRefs = new HashMap<>();
+		symRefs.put("HEAD", "refs/heads/main");
+
+		BasePackConnection.updateWithSymRefs(refMap, symRefs);
+
+		assertThat(refMap, hasKey("HEAD"));
+		final Ref headRef = refMap.get("HEAD");
+		assertThat(headRef, instanceOf(SymbolicRef.class));
+		final SymbolicRef headSymRef = (SymbolicRef) headRef;
+		assertEquals("HEAD", headSymRef.getName());
+		assertSame(mainRef, headSymRef.getTarget());
+	}
+
+	@Test
+	public void testUpdateWithSymRefsReplaces() {
+		final Ref mainRef = new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE,
+				"refs/heads/main", ObjectId.fromString(
+						"0000000000000000000000000000000000000001"));
+
+		final Map<String, Ref> refMap = new HashMap<>();
+		refMap.put(mainRef.getName(), mainRef);
+		refMap.put("HEAD", new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "HEAD",
+				mainRef.getObjectId()));
+		refMap.put("refs/heads/other",
+				new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "refs/heads/other",
+						ObjectId.fromString(
+								"0000000000000000000000000000000000000002")));
+
+		final Map<String, String> symRefs = new HashMap<>();
+		symRefs.put("HEAD", "refs/heads/main");
+
+		BasePackConnection.updateWithSymRefs(refMap, symRefs);
+
+		assertThat(refMap, hasKey("HEAD"));
+		final Ref headRef = refMap.get("HEAD");
+		assertThat(headRef, instanceOf(SymbolicRef.class));
+		final SymbolicRef headSymRef = (SymbolicRef) headRef;
+		assertEquals("HEAD", headSymRef.getName());
+		assertSame(mainRef, headSymRef.getTarget());
+	}
+
+	@Test
+	public void testUpdateWithSymRefsWithIndirectsAdds() {
+		final Ref mainRef = new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE,
+				"refs/heads/main", ObjectId.fromString(
+						"0000000000000000000000000000000000000001"));
+
+		final Map<String, Ref> refMap = new HashMap<>();
+		refMap.put(mainRef.getName(), mainRef);
+		refMap.put("refs/heads/other",
+				new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "refs/heads/other",
+						ObjectId.fromString(
+								"0000000000000000000000000000000000000002")));
+
+		final Map<String, String> symRefs = new LinkedHashMap<>(); // Ordered
+		symRefs.put("refs/heads/sym3", "refs/heads/sym2"); // Forward reference
+		symRefs.put("refs/heads/sym1", "refs/heads/main");
+		symRefs.put("refs/heads/sym2", "refs/heads/sym1"); // Backward reference
+
+		BasePackConnection.updateWithSymRefs(refMap, symRefs);
+
+		assertThat(refMap, hasKey("refs/heads/sym1"));
+		final Ref sym1Ref = refMap.get("refs/heads/sym1");
+		assertThat(sym1Ref, instanceOf(SymbolicRef.class));
+		final SymbolicRef sym1SymRef = (SymbolicRef) sym1Ref;
+		assertEquals("refs/heads/sym1", sym1SymRef.getName());
+		assertSame(mainRef, sym1SymRef.getTarget());
+
+		assertThat(refMap, hasKey("refs/heads/sym2"));
+		final Ref sym2Ref = refMap.get("refs/heads/sym2");
+		assertThat(sym2Ref, instanceOf(SymbolicRef.class));
+		final SymbolicRef sym2SymRef = (SymbolicRef) sym2Ref;
+		assertEquals("refs/heads/sym2", sym2SymRef.getName());
+		assertSame(sym1SymRef, sym2SymRef.getTarget());
+
+		assertThat(refMap, hasKey("refs/heads/sym3"));
+		final Ref sym3Ref = refMap.get("refs/heads/sym3");
+		assertThat(sym3Ref, instanceOf(SymbolicRef.class));
+		final SymbolicRef sym3SymRef = (SymbolicRef) sym3Ref;
+		assertEquals("refs/heads/sym3", sym3SymRef.getName());
+		assertSame(sym2SymRef, sym3SymRef.getTarget());
+	}
+
+	@Test
+	public void testUpdateWithSymRefsWithIndirectsReplaces() {
+		final Ref mainRef = new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE,
+				"refs/heads/main", ObjectId.fromString(
+						"0000000000000000000000000000000000000001"));
+
+		final Map<String, Ref> refMap = new HashMap<>();
+		refMap.put(mainRef.getName(), mainRef);
+		refMap.put("refs/heads/sym1", new ObjectIdRef.Unpeeled(
+				Ref.Storage.LOOSE, "refs/heads/sym1", mainRef.getObjectId()));
+		refMap.put("refs/heads/sym2", new ObjectIdRef.Unpeeled(
+				Ref.Storage.LOOSE, "refs/heads/sym2", mainRef.getObjectId()));
+		refMap.put("refs/heads/sym3", new ObjectIdRef.Unpeeled(
+				Ref.Storage.LOOSE, "refs/heads/sym3", mainRef.getObjectId()));
+		refMap.put("refs/heads/other",
+				new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "refs/heads/other",
+						ObjectId.fromString(
+								"0000000000000000000000000000000000000002")));
+
+		final Map<String, String> symRefs = new LinkedHashMap<>(); // Ordered
+		symRefs.put("refs/heads/sym3", "refs/heads/sym2"); // Forward reference
+		symRefs.put("refs/heads/sym1", "refs/heads/main");
+		symRefs.put("refs/heads/sym2", "refs/heads/sym1"); // Backward reference
+
+		BasePackConnection.updateWithSymRefs(refMap, symRefs);
+
+		assertThat(refMap, hasKey("refs/heads/sym1"));
+		final Ref sym1Ref = refMap.get("refs/heads/sym1");
+		assertThat(sym1Ref, instanceOf(SymbolicRef.class));
+		final SymbolicRef sym1SymRef = (SymbolicRef) sym1Ref;
+		assertEquals("refs/heads/sym1", sym1SymRef.getName());
+		assertSame(mainRef, sym1SymRef.getTarget());
+
+		assertThat(refMap, hasKey("refs/heads/sym2"));
+		final Ref sym2Ref = refMap.get("refs/heads/sym2");
+		assertThat(sym2Ref, instanceOf(SymbolicRef.class));
+		final SymbolicRef sym2SymRef = (SymbolicRef) sym2Ref;
+		assertEquals("refs/heads/sym2", sym2SymRef.getName());
+		assertSame(sym1SymRef, sym2SymRef.getTarget());
+
+		assertThat(refMap, hasKey("refs/heads/sym3"));
+		final Ref sym3Ref = refMap.get("refs/heads/sym3");
+		assertThat(sym3Ref, instanceOf(SymbolicRef.class));
+		final SymbolicRef sym3SymRef = (SymbolicRef) sym3Ref;
+		assertEquals("refs/heads/sym3", sym3SymRef.getName());
+		assertSame(sym2SymRef, sym3SymRef.getTarget());
+	}
+
+	@Test
+	public void testUpdateWithSymRefsIgnoresSelfReference() {
+		final Ref mainRef = new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE,
+				"refs/heads/main", ObjectId.fromString(
+						"0000000000000000000000000000000000000001"));
+
+		final Map<String, Ref> refMap = new HashMap<>();
+		refMap.put(mainRef.getName(), mainRef);
+		refMap.put("refs/heads/other",
+				new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "refs/heads/other",
+						ObjectId.fromString(
+								"0000000000000000000000000000000000000002")));
+
+		final Map<String, String> symRefs = new LinkedHashMap<>();
+		symRefs.put("refs/heads/sym1", "refs/heads/sym1");
+
+		BasePackConnection.updateWithSymRefs(refMap, symRefs);
+
+		assertEquals(2, refMap.size());
+		assertThat(refMap, not(hasKey("refs/heads/sym1")));
+	}
+
+	@Test
+	public void testUpdateWithSymRefsIgnoreCircularReference() {
+		final Ref mainRef = new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE,
+				"refs/heads/main", ObjectId.fromString(
+						"0000000000000000000000000000000000000001"));
+
+		final Map<String, Ref> refMap = new HashMap<>();
+		refMap.put(mainRef.getName(), mainRef);
+		refMap.put("refs/heads/other",
+				new ObjectIdRef.Unpeeled(Ref.Storage.LOOSE, "refs/heads/other",
+						ObjectId.fromString(
+								"0000000000000000000000000000000000000002")));
+
+		final Map<String, String> symRefs = new LinkedHashMap<>();
+		symRefs.put("refs/heads/sym2", "refs/heads/sym1");
+		symRefs.put("refs/heads/sym1", "refs/heads/sym2");
+
+		BasePackConnection.updateWithSymRefs(refMap, symRefs);
+
+		assertEquals(2, refMap.size());
+		assertThat(refMap, not(hasKey("refs/heads/sym1")));
+		assertThat(refMap, not(hasKey("refs/heads/sym2")));
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PacketLineInTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PacketLineInTest.java
index 5d7f881..7f03357 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PacketLineInTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PacketLineInTest.java
@@ -12,8 +12,8 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.ByteArrayInputStream;
@@ -111,20 +111,25 @@ public void testReadString_Len0004() throws IOException {
 		final String act = in.readString();
 		assertEquals("", act);
 		assertFalse(PacketLineIn.isEnd(act));
+		assertFalse(PacketLineIn.isDelimiter(act));
 		assertEOF();
 	}
 
 	@Test
 	public void testReadString_End() throws IOException {
 		init("0000");
-		assertTrue(PacketLineIn.isEnd(in.readString()));
+		String act = in.readString();
+		assertTrue(PacketLineIn.isEnd(act));
+		assertFalse(PacketLineIn.isDelimiter(act));
 		assertEOF();
 	}
 
 	@Test
 	public void testReadString_Delim() throws IOException {
 		init("0001");
-		assertTrue(PacketLineIn.isDelimiter(in.readString()));
+		String act = in.readString();
+		assertTrue(PacketLineIn.isDelimiter(act));
+		assertFalse(PacketLineIn.isEnd(act));
 		assertEOF();
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
index ce546e3..5045e94 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
@@ -38,6 +38,7 @@
 import org.eclipse.jgit.internal.storage.pack.CachedPack;
 import org.eclipse.jgit.internal.storage.pack.CachedPackUriProvider;
 import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectInserter;
@@ -370,7 +371,8 @@ private ByteArrayInputStream uploadPackSetup(String version,
 
 		ByteArrayInputStream send = linesAsInputStream(inputLines);
 
-		server.getConfig().setString("protocol", null, "version", version);
+		server.getConfig().setString(ConfigConstants.CONFIG_PROTOCOL_SECTION,
+				null, ConfigConstants.CONFIG_KEY_VERSION, version);
 		UploadPack up = new UploadPack(server);
 		if (postConstructionSetup != null) {
 			postConstructionSetup.accept(up);
@@ -435,8 +437,9 @@ private ByteArrayInputStream uploadPackV2(
 			Consumer<UploadPack> postConstructionSetup,
 			String... inputLines)
 			throws Exception {
-		ByteArrayInputStream recvStream =
-				uploadPackSetup("2", postConstructionSetup, inputLines);
+		ByteArrayInputStream recvStream = uploadPackSetup(
+				TransferConfig.ProtocolVersion.V2.version(),
+				postConstructionSetup, inputLines);
 		PacketLineIn pckIn = new PacketLineIn(recvStream);
 
 		// drain capabilities
@@ -476,9 +479,11 @@ public void onFetch(FetchV2Request req) {
 	@Test
 	public void testV2Capabilities() throws Exception {
 		TestV2Hook hook = new TestV2Hook();
-		ByteArrayInputStream recvStream = uploadPackSetup( "2",
-				(UploadPack up) -> {up.setProtocolV2Hook(hook);},
-				PacketLineIn.end());
+		ByteArrayInputStream recvStream = uploadPackSetup(
+				TransferConfig.ProtocolVersion.V2.version(),
+				(UploadPack up) -> {
+					up.setProtocolV2Hook(hook);
+				}, PacketLineIn.end());
 		PacketLineIn pckIn = new PacketLineIn(recvStream);
 		assertThat(hook.capabilitiesRequest, notNullValue());
 		assertThat(pckIn.readString(), is("version 2"));
@@ -498,8 +503,9 @@ public void testV2Capabilities() throws Exception {
 	private void checkAdvertisedIfAllowed(String configSection, String configName,
 			String fetchCapability) throws Exception {
 		server.getConfig().setBoolean(configSection, null, configName, true);
-		ByteArrayInputStream recvStream =
-				uploadPackSetup("2", null, PacketLineIn.end());
+		ByteArrayInputStream recvStream = uploadPackSetup(
+				TransferConfig.ProtocolVersion.V2.version(), null,
+				PacketLineIn.end());
 		PacketLineIn pckIn = new PacketLineIn(recvStream);
 
 		assertThat(pckIn.readString(), is("version 2"));
@@ -522,8 +528,9 @@ private void checkAdvertisedIfAllowed(String configSection, String configName,
 	private void checkUnadvertisedIfUnallowed(String configSection,
 			String configName, String fetchCapability) throws Exception {
 		server.getConfig().setBoolean(configSection, null, configName, false);
-		ByteArrayInputStream recvStream =
-				uploadPackSetup("2", null, PacketLineIn.end());
+		ByteArrayInputStream recvStream = uploadPackSetup(
+				TransferConfig.ProtocolVersion.V2.version(), null,
+				PacketLineIn.end());
 		PacketLineIn pckIn = new PacketLineIn(recvStream);
 
 		assertThat(pckIn.readString(), is("version 2"));
@@ -574,8 +581,9 @@ public void testV2CapabilitiesAdvertiseSidebandAll() throws Exception {
 	public void testV2CapabilitiesRefInWantNotAdvertisedIfAdvertisingForbidden() throws Exception {
 		server.getConfig().setBoolean("uploadpack", null, "allowrefinwant", true);
 		server.getConfig().setBoolean("uploadpack", null, "advertiserefinwant", false);
-		ByteArrayInputStream recvStream =
-				uploadPackSetup("2", null, PacketLineIn.end());
+		ByteArrayInputStream recvStream = uploadPackSetup(
+				TransferConfig.ProtocolVersion.V2.version(), null,
+				PacketLineIn.end());
 		PacketLineIn pckIn = new PacketLineIn(recvStream);
 
 		assertThat(pckIn.readString(), is("version 2"));
@@ -739,7 +747,10 @@ public void testV2LsRefsServerOptions() throws Exception {
 				PacketLineIn.end() };
 
 		TestV2Hook testHook = new TestV2Hook();
-		uploadPackSetup("2", (UploadPack up) -> {up.setProtocolV2Hook(testHook);}, lines);
+		uploadPackSetup(TransferConfig.ProtocolVersion.V2.version(),
+				(UploadPack up) -> {
+					up.setProtocolV2Hook(testHook);
+				}, lines);
 
 		LsRefsV2Request req = testHook.lsRefsRequest;
 		assertEquals(2, req.getServerOptions().size());
@@ -1559,7 +1570,10 @@ public void testV2FetchServerOptions() throws Exception {
 				PacketLineIn.end() };
 
 		TestV2Hook testHook = new TestV2Hook();
-		uploadPackSetup("2", (UploadPack up) -> {up.setProtocolV2Hook(testHook);}, lines);
+		uploadPackSetup(TransferConfig.ProtocolVersion.V2.version(),
+				(UploadPack up) -> {
+					up.setProtocolV2Hook(testHook);
+				}, lines);
 
 		FetchV2Request req = testHook.fetchRequest;
 		assertNotNull(req);
@@ -2253,7 +2267,9 @@ public void testGetPeerAgentProtocolV0() throws Exception {
 
 	@Test
 	public void testGetPeerAgentProtocolV2() throws Exception {
-		server.getConfig().setString("protocol", null, "version", "2");
+		server.getConfig().setString(ConfigConstants.CONFIG_PROTOCOL_SECTION,
+				null, ConfigConstants.CONFIG_KEY_VERSION,
+				TransferConfig.ProtocolVersion.V2.version());
 
 		RevCommit one = remote.commit().message("1").create();
 		remote.update("one", one);
diff --git a/org.eclipse.jgit/.settings/.api_filters b/org.eclipse.jgit/.settings/.api_filters
index 538c6f7..035ed37 100644
--- a/org.eclipse.jgit/.settings/.api_filters
+++ b/org.eclipse.jgit/.settings/.api_filters
@@ -1,5 +1,14 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <component id="org.eclipse.jgit" version="2">
+    <resource path="src/org/eclipse/jgit/lib/ConfigConstants.java" type="org.eclipse.jgit.lib.ConfigConstants">
+        <filter id="1141899266">
+            <message_arguments>
+                <message_argument value="5.9"/>
+                <message_argument value="5.10"/>
+                <message_argument value="CONFIG_PROTOCOL_SECTION"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/lib/TypedConfigGetter.java" type="org.eclipse.jgit.lib.TypedConfigGetter">
         <filter id="404000815">
             <message_arguments>
@@ -36,4 +45,13 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="src/org/eclipse/jgit/transport/TransferConfig.java" type="org.eclipse.jgit.transport.TransferConfig$ProtocolVersion">
+        <filter id="1175453698">
+            <message_arguments>
+                <message_argument value="5.9"/>
+                <message_argument value="5.10"/>
+                <message_argument value="org.eclipse.jgit.transport.TransferConfig.ProtocolVersion"/>
+            </message_arguments>
+        </filter>
+    </resource>
 </component>
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
index 30d7f9a..aba86fc 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
@@ -413,6 +413,10 @@ private Ref findBranchToCheckout(FetchResult result) {
 			return null;
 		}
 
+		if (idHEAD != null && idHEAD.isSymbolic()) {
+			return idHEAD.getTarget();
+		}
+
 		Ref master = result.getAdvertisedRef(Constants.R_HEADS
 				+ Constants.MASTER);
 		ObjectId objectId = master != null ? master.getObjectId() : null;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackFile.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackFile.java
index 254c020..e112fe7 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackFile.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackFile.java
@@ -650,6 +650,7 @@ synchronized boolean endWindowCache() {
 
 	private void doOpen() throws IOException {
 		if (invalid) {
+			openFail(true, invalidatingCause);
 			throw new PackInvalidException(packFile, invalidatingCause);
 		}
 		try {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
index 4fcf8e2..834fff5 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
@@ -93,6 +93,12 @@ public final class ConfigConstants {
 	public static final String CONFIG_GPG_SECTION = "gpg";
 
 	/**
+	 * The "protocol" section
+	 * @since 5.9
+	 */
+	public static final String CONFIG_PROTOCOL_SECTION = "protocol";
+
+	/**
 	 * The "format" key
 	 * @since 5.2
 	 */
@@ -685,7 +691,7 @@ public final class ConfigConstants {
 	public static final String CONFIG_INDEX_SECTION = "index";
 
 	/**
-	 * The "index.version" key
+	 * The "version" key
 	 *
 	 * @since 5.9
 	 */
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 1417fae..3a36398 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackConnection.java
@@ -21,8 +21,11 @@
 import java.io.OutputStream;
 import java.text.MessageFormat;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.Map;
 import java.util.Set;
 
 import org.eclipse.jgit.errors.InvalidObjectIdException;
@@ -35,6 +38,7 @@
 import org.eclipse.jgit.lib.ObjectIdRef;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.SymbolicRef;
 import org.eclipse.jgit.util.io.InterruptTimer;
 import org.eclipse.jgit.util.io.TimeoutInputStream;
 import org.eclipse.jgit.util.io.TimeoutOutputStream;
@@ -49,6 +53,8 @@
  */
 abstract class BasePackConnection extends BaseConnection {
 
+	protected static final String CAPABILITY_SYMREF_PREFIX = "symref="; //$NON-NLS-1$
+
 	/** The repository this transport fetches into, or pushes out of. */
 	protected final Repository local;
 
@@ -228,10 +234,109 @@ private void readAdvertisedRefsImpl() throws IOException {
 					throw duplicateAdvertisement(name);
 			}
 		}
+		updateWithSymRefs(avail, extractSymRefsFromCapabilities(remoteCapablities));
 		available(avail);
 	}
 
 	/**
+	 * Finds values in the given capabilities of the form:
+	 *
+	 * <pre>
+	 * symref=<em>source</em>:<em>target</em>
+	 * </pre>
+	 *
+	 * And returns a Map of source->target entries.
+	 *
+	 * @param capabilities
+	 *            the capabilities lines
+	 * @return a Map of the symref entries from capabilities
+	 * @throws NullPointerException
+	 *             if capabilities, or any entry in it, is null
+	 */
+	static Map<String, String> extractSymRefsFromCapabilities(Collection<String> capabilities) {
+		final Map<String, String> symRefs = new LinkedHashMap<>();
+		for (String option : capabilities) {
+			if (option.startsWith(CAPABILITY_SYMREF_PREFIX)) {
+				String[] symRef = option
+						.substring(CAPABILITY_SYMREF_PREFIX.length())
+						.split(":", 2); //$NON-NLS-1$
+				if (symRef.length == 2) {
+					symRefs.put(symRef[0], symRef[1]);
+				}
+			}
+		}
+		return symRefs;
+	}
+
+	/**
+	 * Updates the given refMap with {@link SymbolicRef}s defined by the given
+	 * symRefs.
+	 * <p>
+	 * For each entry, symRef, in symRefs, whose value is a key in refMap, adds
+	 * a new entry to refMap with that same key and value of a new
+	 * {@link SymbolicRef} with source=symRef.key and
+	 * target=refMap.get(symRef.value), then removes that entry from symRefs.
+	 * <p>
+	 * If refMap already contains an entry for symRef.key, it is replaced.
+	 * </p>
+	 * </p>
+	 * <p>
+	 * For example, given:
+	 * </p>
+	 *
+	 * <pre>
+	 * refMap.put("refs/heads/main", ref);
+	 * symRefs.put("HEAD", "refs/heads/main");
+	 * </pre>
+	 *
+	 * then:
+	 *
+	 * <pre>
+	 * updateWithSymRefs(refMap, symRefs);
+	 * </pre>
+	 *
+	 * has the <em>effect</em> of:
+	 *
+	 * <pre>
+	 * refMap.put("HEAD",
+	 * 		new SymbolicRef("HEAD", refMap.get(symRefs.remove("HEAD"))))
+	 * </pre>
+	 * <p>
+	 * Any entry in symRefs whose value is not a key in refMap is ignored. Any
+	 * circular symRefs are ignored.
+	 * </p>
+	 * <p>
+	 * Upon completion, symRefs will contain only any unresolvable entries.
+	 * </p>
+	 *
+	 * @param refMap
+	 *            a non-null, modifiable, Map to update, and the provider of
+	 *            symref targets.
+	 * @param symRefs
+	 *            a non-null, modifiable, Map of symrefs.
+	 * @throws NullPointerException
+	 *             if refMap or symRefs is null
+	 */
+	static void updateWithSymRefs(Map<String, Ref> refMap, Map<String, String> symRefs) {
+		boolean haveNewRefMapEntries = !refMap.isEmpty();
+		while (!symRefs.isEmpty() && haveNewRefMapEntries) {
+			haveNewRefMapEntries = false;
+			final Iterator<Map.Entry<String, String>> iterator = symRefs.entrySet().iterator();
+			while (iterator.hasNext()) {
+				final Map.Entry<String, String> symRef = iterator.next();
+				if (!symRefs.containsKey(symRef.getValue())) { // defer forward reference
+					final Ref r = refMap.get(symRef.getValue());
+					if (r != null) {
+						refMap.put(symRef.getKey(), new SymbolicRef(symRef.getKey(), r));
+						haveNewRefMapEntries = true;
+						iterator.remove();
+					}
+				}
+			}
+		}
+	}
+
+	/**
 	 * Create an exception to indicate problems finding a remote repository. The
 	 * caller is expected to throw the returned exception.
 	 *
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 cc577fa..0b38159 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
@@ -21,6 +21,7 @@
 import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.internal.storage.file.LazyObjectIdSetFile;
 import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Config.SectionParser;
 import org.eclipse.jgit.lib.ObjectChecker;
 import org.eclipse.jgit.lib.ObjectIdSet;
@@ -60,11 +61,19 @@ public enum FsckMode {
 	}
 
 	/**
-	 * A git configuration variable for which versions of the Git protocol to prefer.
-	 * Used in protocol.version.
+	 * A git configuration variable for which versions of the Git protocol to
+	 * prefer. Used in protocol.version.
+	 *
+	 * @since 5.9
 	 */
-	enum ProtocolVersion {
+	public enum ProtocolVersion {
+		/**
+		 * Git wire protocol version 0 (the default).
+		 */
 		V0("0"), //$NON-NLS-1$
+		/**
+		 * Git wire protocol version 2.
+		 */
 		V2("2"); //$NON-NLS-1$
 
 		final String name;
@@ -73,6 +82,15 @@ enum ProtocolVersion {
 			this.name = name;
 		}
 
+		/**
+		 * Returns version number
+		 *
+		 * @return string version
+		 */
+		public String version() {
+			return name;
+		}
+
 		@Nullable
 		static ProtocolVersion parse(@Nullable String name) {
 			if (name == null) {
@@ -177,7 +195,9 @@ public TransferConfig(Config rc) {
 				"uploadpack", "allowreachablesha1inwant", false);
 		allowFilter = rc.getBoolean(
 				"uploadpack", "allowfilter", false);
-		protocolVersion = ProtocolVersion.parse(rc.getString("protocol", null, "version"));
+		protocolVersion = ProtocolVersion.parse(rc
+				.getString(ConfigConstants.CONFIG_PROTOCOL_SECTION, null,
+						ConfigConstants.CONFIG_KEY_VERSION));
 		hideRefs = rc.getStringList("uploadpack", null, "hiderefs");
 		allowSidebandAll = rc.getBoolean(
 				"uploadpack", "allowsidebandall", false);
diff --git a/pom.xml b/pom.xml
index 4f4ab42..2ee3d0f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -151,7 +151,7 @@
     <maven.compiler.target>1.8</maven.compiler.target>
     <bundle-manifest>${project.build.directory}/META-INF/MANIFEST.MF</bundle-manifest>
 
-    <jgit-last-release-version>5.8.0.202006091008-r</jgit-last-release-version>
+    <jgit-last-release-version>5.9.0.202009080501-r</jgit-last-release-version>
     <apache-sshd-version>2.4.0</apache-sshd-version>
     <jsch-version>0.1.55</jsch-version>
     <jzlib-version>1.1.1</jzlib-version>
@@ -299,7 +299,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-pmd-plugin</artifactId>
-          <version>3.13.0</version>
+          <version>3.14.0</version>
           <configuration>
             <sourceEncoding>utf-8</sourceEncoding>
             <minimumTokens>100</minimumTokens>