[TINKERPOP-1693] Tree may produce incorrect results when nodes are not unique

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 3.2.5
• Component/s: process
• Assignee: Marko A. Rodriguez
• Reporter: Stephen Mallette
• Created: 16/Jun/17 12:15
• Updated: 30/Jun/17 18:47
• Resolved: 30/Jun/17 18:47

Description

Consider the following:

gremlin> g = TinkerFactory.createModern().traversal()
==>graphtraversalsource[tinkergraph[vertices:6 edges:6], standard]
gremlin> g.V(1).repeat(out()).emit().tree()
==>[v[1]:[v[2]:[],v[3]:[],v[4]:[v[3]:[],v[5]:[]]]]
gremlin> g.V(1).repeat(out()).emit().tree().by(label)
==>[person:[software:[],person:[software:[]]]]
gremlin> g.V(1).repeat(out()).emit().tree().by("name")
==>[marko:[vadas:[],josh:[ripple:[],lop:[]],lop:[]]]

Since Tree extends HashMap we end up with keys having to be unique and when they aren't we lose some of the tree structure.

Issue Links

• relates to: TINKERPOP-1684 Improper results with union() in a by()
• relates to: TINKERPOP-1374 Consider making Tree an interface
• supercedes: TINKERPOP-1710 Add a note on tree() by-modulation and uniqueness of tree branches.