"JGitInternalException: Create branch returned unexpected result NO_CHANGE" in BRMS cluster

Issue

• When I start BRMS cluster, node1 successfully started but node2 throws the Exception below and gets stuck.

07:45:18,779 ERROR [org.uberfire.io.impl.AbstractIOService] (Thread-102) Failed to register filesystem default://MyRepo?sync=git://host1:9418/MyRepo&force with DEFAULT_FS_TYPE. Returning null.: org.uberfire.java.nio.IOException: java.lang.RuntimeException: org.eclipse.jgit.api.errors.JGitInternalException: Create branch returned unexpected result NO_CHANGE
        at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.getFileSystem(JGitFileSystemProvider.java:656) [uberfire-nio2-jgit-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        at org.uberfire.java.nio.file.FileSystems.getFileSystem(FileSystems.java:66) [uberfire-nio2-api-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        at org.uberfire.io.impl.AbstractIOService.getFileSystem(AbstractIOService.java:214) [uberfire-io-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        at org.uberfire.ext.metadata.io.IOServiceIndexedImpl.getFileSystem(IOServiceIndexedImpl.java:176) [uberfire-metadata-commons-io-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        at org.uberfire.io.impl.cluster.IOServiceClusterImpl$3$1$1.run(IOServiceClusterImpl.java:193) [uberfire-io-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [rt.jar:1.7.0_80]
        at java.util.concurrent.FutureTask.run(FutureTask.java:262) [rt.jar:1.7.0_80]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_80]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_80]
        at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_80]
Caused by: java.lang.RuntimeException: org.eclipse.jgit.api.errors.JGitInternalException: Create branch returned unexpected result NO_CHANGE
        at org.uberfire.java.nio.fs.jgit.util.JGitUtil.syncRepository(JGitUtil.java:318) [uberfire-nio2-jgit-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.getFileSystem(JGitFileSystemProvider.java:652) [uberfire-nio2-jgit-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        ... 9 more
Caused by: org.eclipse.jgit.api.errors.JGitInternalException: Create branch returned unexpected result NO_CHANGE
        at org.eclipse.jgit.api.CreateBranchCommand.call(CreateBranchCommand.java:207) [org.eclipse.jgit-3.3.2.201404171909-r.jar:3.3.2.201404171909-r]
        at org.uberfire.java.nio.fs.jgit.util.JGitUtil.syncRepository(JGitUtil.java:295) [uberfire-nio2-jgit-0.5.7.Final-redhat-1.jar:0.5.7.Final-redhat-1]
        ... 10 more

• I deleted the local "HEAD" branch and remote tracking branch "upstream/HEAD". Then I get a different Exception message

ERROR [org.uberfire.io.impl.AbstractIOService] (Thread-107) Failed to register filesystem default://MyRepo?sync=git://host1:9418/MyRepo&force with DEFAULT_FS_TYPE. Returning null.: org.uberfire.java.nio.IOException: java.lang.RuntimeException: org.eclipse.jgit.api.errors.RefNotFoundException: Ref upstream/HEAD can not be resolved
    at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.getFileSystem(JGitFileSystemProvider.java:666) [uberfire-nio2-jgit-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    at org.uberfire.java.nio.file.FileSystems.getFileSystem(FileSystems.java:66) [uberfire-nio2-api-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    at org.uberfire.io.impl.AbstractIOService.getFileSystem(AbstractIOService.java:214) [uberfire-io-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    at org.uberfire.ext.metadata.io.IOServiceIndexedImpl.getFileSystem(IOServiceIndexedImpl.java:176) [uberfire-metadata-commons-io-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    at org.uberfire.io.impl.cluster.IOServiceClusterImpl$3$1$1.run(IOServiceClusterImpl.java:193) [uberfire-io-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [rt.jar:1.7.0_80]
    at java.util.concurrent.FutureTask.run(FutureTask.java:262) [rt.jar:1.7.0_80]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_80]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_80]
    at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_80]
Caused by: java.lang.RuntimeException: org.eclipse.jgit.api.errors.RefNotFoundException: Ref upstream/HEAD can not be resolved
    at org.uberfire.java.nio.fs.jgit.util.JGitUtil.syncRepository(JGitUtil.java:318) [uberfire-nio2-jgit-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.getFileSystem(JGitFileSystemProvider.java:662) [uberfire-nio2-jgit-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    ... 9 more
Caused by: org.eclipse.jgit.api.errors.RefNotFoundException: Ref upstream/HEAD can not be resolved
    at org.eclipse.jgit.api.CreateBranchCommand.getStartPoint(CreateBranchCommand.java:291) [org.eclipse.jgit-3.3.2.201404171909-r.jar:3.3.2.201404171909-r]
    at org.eclipse.jgit.api.CreateBranchCommand.call(CreateBranchCommand.java:136) [org.eclipse.jgit-3.3.2.201404171909-r.jar:3.3.2.201404171909-r]
    at org.uberfire.java.nio.fs.jgit.util.JGitUtil.syncRepository(JGitUtil.java:307) [uberfire-nio2-jgit-0.5.8.Final-redhat-1.jar:0.5.8.Final-redhat-1]
    ... 10 more