[HIVE-23295] Possible NPE when on getting predicate literal list when dynamic values are not available

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0-alpha-1
• Component/s: storage-api
• Assignee: Attila Magyar
• Reporter: Attila Magyar
• Created: 24/Apr/20 09:49
• Updated: 17/Nov/22 08:50
• Resolved: 27/Apr/20 23:04

Description

getLiteralList() in SearchArgumentImpl$PredicateLeafImpl returns null if dynamic values are not available.

@Override
public List<Object> getLiteralList() {
  if (literalList != null && literalList.size() > 0 && literalList.get(0) instanceof LiteralDelegate) {
    List<Object> newLiteraList = new ArrayList<Object>();
    try {
      for (Object litertalObj : literalList) {
        Object literal = ((LiteralDelegate) litertalObj).getLiteral();
        if (literal != null) {
          newLiteraList.add(literal);
        }
      }
    } catch (NoDynamicValuesException err) {
      LOG.debug("Error while retrieving literalList, returning null", err);
      return null;
    }
    return newLiteraList;
  }
  return literalList;
} 

 

There are multiple call sites where the return value is used without a null check. E.g:  leaf.getLiteralList().stream(). 

 

The return null was added as part of HIVE-18827 to avoid having an unimportant warning message when dynamic values have not been delivered yet.

 

sershe, jdere, I propose return an empty list instead of null in a case like this. What do you think?