Merge branch 'stable-3.1' into stable-3.2

* stable-3.1:
  Remove Hugo Arès from developers section in pom.xml files
  ElasticContainer: Upgrade V6_8 to elasticsearch 6.8.10
  Upgrade elasticsearch-rest-client to 7.7.1
  ElasticContainer: Upgrade V7_7 to elasticsearch 7.7.1
  Support /COMMIT_MSG for change edit REST endpoints
  IntBlob: Add debug log when storing value on ref
  RepoSequence: Add debug log when acquiring new sequence batch
  Bazel: Remove version suffix from servlet-api-3_1 rule
  Update no-new-changes error doc
  Ignore WIP changes in "CCed on" dashboard section
  Sequences: Introduce constants for configuration keys/values
  RepoSequence: Add debug log of batch size
  Move Flogger to nongoogle.bzl
  DefaultRefFilter#canSeeSingleChangeRef: Do not fail for invalid change refs
  Upgrade testcontainers to 1.14.3
  Add missing documentation of notedb.changes.sequenceBatchSize
  Enable rolling upgrade to next versions

Change-Id: I73cfa328b97619440f25374c0380760dd54ec646

java/com/google/gerrit/server/permissions/DefaultRefFilter.java

@@ -570,7 +570,12 @@ class DefaultRefFilter {
     // even if the change is not part of the set of most recent changes that
     // SearchingChangeCacheImpl returns.
     Change.Id cId = Change.Id.fromRef(refName);
-    requireNonNull(cId, () -> String.format("invalid change id for ref %s", refName));
+    if (cId == null) {
+      // The ref is not a valid change ref. Treat it as non-visible since it's not representing a
+      // change.
+      logger.atWarning().log("invalid change ref %s is not visible", refName);
+      return false;
+    }
     ChangeNotes notes;
     try {
       notes = changeNotesFactory.create(projectState.getNameKey(), cId);