[PIG-1843] NPE in schema generation

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0
• Fix Version/s: 0.8.1
• Hadoop Flags: Reviewed
• Assignee: Daniel Dai
• Reporter: Daniel Dai
• Created: 05/Feb/11 02:42
• Updated: 25/Apr/11 21:27
• Resolved: 18/Feb/11 01:48

Description

Hit NPE in following script:

a = load 'table_testBagDereferenceInMiddle2' as (a0:chararray);
b = foreach a generate MapGenerate(STRSPLIT(a0).$0));

public class MapGenerate extends EvalFunc<Map> {
    @Override
    public Map exec(Tuple input) throws IOException {
        Map m = new HashMap();
        m.put("key", new Integer(input.size()));
        return m;
    }
    
    @Override
    public Schema outputSchema(Schema input) {
        return new Schema(new Schema.FieldSchema(getSchemaName("parselong", input), DataType.MAP));
    }
}

Error message:
Caused by: java.lang.NullPointerException
at org.apache.pig.EvalFunc.getSchemaName(EvalFunc.java:76)
at string.PARSELONG.outputSchema(PARSELONG.java:63)
at org.apache.pig.newplan.logical.expression.UserFuncExpression.getFieldSchema(UserFuncExpression.java:154)
at org.apache.pig.newplan.logical.optimizer.FieldSchemaResetter.execute(SchemaResetter.java:192)
at org.apache.pig.newplan.logical.expression.AllSameExpressionVisitor.visit(AllSameExpressionVisitor.java:143)
at org.apache.pig.newplan.logical.expression.UserFuncExpression.accept(UserFuncExpression.java:71)
at org.apache.pig.newplan.ReverseDependencyOrderWalker.walk(ReverseDependencyOrderWalker.java:70)
at org.apache.pig.newplan.PlanVisitor.visit(PlanVisitor.java:50)
at org.apache.pig.newplan.logical.optimizer.SchemaResetter.visit(SchemaResetter.java:104)
at org.apache.pig.newplan.logical.relational.LOGenerate.accept(LOGenerate.java:240)
at org.apache.pig.newplan.DependencyOrderWalker.walk(DependencyOrderWalker.java:75)
at org.apache.pig.newplan.logical.optimizer.SchemaResetter.visit(SchemaResetter.java:93)
at org.apache.pig.newplan.logical.relational.LOForEach.accept(LOForEach.java:73)
at org.apache.pig.newplan.DependencyOrderWalker.walk(DependencyOrderWalker.java:75)
at org.apache.pig.newplan.PlanVisitor.visit(PlanVisitor.java:50)
at org.apache.pig.backend.hadoop.executionengine.HExecutionEngine.compile(HExecutionEngine.java:279)
at org.apache.pig.PigServer.compilePp(PigServer.java:1480)
at org.apache.pig.PigServer.explain(PigServer.java:1042)