Merge branch 'stable-6.3' into stable-6.4

* stable-6.3:
  [bazel] Move ToolTestCase to src folder (6.2)
  GcConcurrentTest: @Ignore flaky testInterruptGc
  Fix CommitTemplateConfigTest
  Fix after_open config and Snapshotting RefDir tests to work with bazel
  [bazel] Skip ConfigTest#testCommitTemplatePathInHomeDirecory
  Demote severity of some error prone bug patterns to warnings
  UploadPack: Fix NPE when traversing a tag chain

Change-Id: I463f8528e623316add204848d551c44d44d04858

diff --cc org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
Simple merge

diff --cc org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
Simple merge