[TINKERPOP-1468] GraphTraversal.optional throws a NPE if no traversal is provided

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 3.2.2
• Component/s: process
• Labels: trivial
• Assignee: Ted Wilmes
• Reporter: Ted Wilmes
• Created: 26/Sep/16 01:34
• Updated: 27/Oct/16 13:51
• Resolved: 27/Oct/16 13:51

Description

GraphTraversal.optional throws a NPE if no traversal is provided. We should probably throw a friendlier exception with instructions to provide a traversal as an argument.

gremlin> g.V().optional()
java.lang.NullPointerException
Type ':help' or ':h' for help.
Display stack trace? [yN]y
java.lang.NullPointerException
	at org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal.optional(GraphTraversal.java:1316)