[TINKERPOP-2257] transaction itty may still be visited after commit

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.3, 3.5.0
• Component/s: server
• Assignee: Stephen Mallette
• Reporter: Stark Arya
• Created: 08/Jul/19 15:38
• Updated: 16/Jul/19 13:42
• Resolved: 16/Jul/19 13:42

Description

Branch: 3.4.0-rc2 
File: org.apache.tinkerpop.gremlin.server.op.AbstractOpProcessor.java
Function: handleIterator
Wherence:

       // we have an empty iterator - happens on stuff like: g.V().iterate()
	if (!itty.hasNext()) \{
	// as there is nothing left to iterate if we are transaction managed then we should execute a
	// commit here before we send back a NO_CONTENT which implies success
	if (managedTransactionsForRequest) attemptCommit(msg, context.getGraphManager(), settings.strictTransactionManagement);
	rhc.writeAndFlush(ResponseMessage.build(msg)
	.code(ResponseStatusCode.NO_CONTENT)
	.statusAttributes(generateStatusAttributes(ctx, msg, ResponseStatusCode.NO_CONTENT, itty, settings))
	.create());
	return;
	}

when attemptCommit called, the transaction finished and the itty handle will Invalid，but
generateStatusAttributes will try to invoke itty.hasNext() again
this will cause some problems and could recurrent when doing follow testing:

1.test data

g.addV('gdb_sample_person').property(id, 'gdb_sample_marko').property('age', 28).property('name', 'marko') g.addV('gdb_sample_person').property(id, 'gdb_sample_vadas').property('age', 27).property('name', 'vadas') g.addV('gdb_sample_person').property(id, 'gdb_sample_josh').property('age', 32).property('name', 'josh') g.addV('gdb_sample_person').property(id, 'gdb_sample_peter').property('age', 35).property('name', 'peter') g.addV('gdb_sample_software').property(id, 'gdb_sample_lop').property('lang', 'java').property('name', 'lop') g.addV('gdb_sample_software').property(id, 'gdb_sample_ripple').property('lang', 'java').property('name', 'ripple')

g.addE('gdb_sample_knows').from(V('gdb_sample_marko')).to(V('gdb_sample_vadas')).property('weight', 0.5f) g.addE('gdb_sample_knows').from(V('gdb_sample_marko')).to(V('gdb_sample_josh')).property('weight', 1.0f) g.addE('gdb_sample_created').from(V('gdb_sample_marko')).to(V('gdb_sample_lop')).property('weight', 0.4f) g.addE('gdb_sample_created').from(V('gdb_sample_josh')).to(V('gdb_sample_lop')).property('weight', 0.4f) g.addE('gdb_sample_created').from(V('gdb_sample_josh')).to(V('gdb_sample_ripple')).property('weight', 1.0f) g.addE('gdb_sample_created').from(V('gdb_sample_peter')).to(V('gdb_sample_lop')).property('weight', 0.2f)

2. test dsl:

g.V().has("gdb_sample_person","name","marko").out("gdb_sample_knows").barrier().both().count().is(lt(1l))