[SOLR-12355] HashJoinStream's use of String::hashCode results in non-matching tuples being considered matches

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 6.0
• Fix Version/s: 7.4
• Component/s: SolrJ
• Assignee: Dennis Gove
• Reporter: Dennis Gove
• Created: 14/May/18 23:43
• Updated: 08/Jun/19 15:12
• Resolved: 18/May/18 21:21

Description

The following strings have been found to have hashCode conflicts and as such can result in HashJoinStream considering two tuples with fields of these values to be considered the same.

"MG!!00TNGP::Mtge::".hashCode() == "MG!!00TNH1::Mtge::".hashCode() 

This means these two tuples are the same if we're comparing on field "foo"

{
  "foo":"MG!!00TNGP::Mtge::"
}
{
  "foo":"MG!!00TNH1::Mtge::"
}

and these two tuples are the same if we're comparing on fields "foo,bar"

{
  "foo":"MG!!00TNGP"
  "bar":"Mtge"
}
{
  "foo":"MG!!00TNH1"
  "bar":"Mtge"
}