[
https://issues.apache.org/jira/browse/CALCITE-2287?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16458174#comment-16458174
]
Julian Hyde commented on CALCITE-2287:
--------------------------------------
I agree with [~zhong.j.yu] about the class-loader problem; or in fact, any
class that implements {{equals(o)}} by calling {{o.equals(this)}}. I think
reversing the arguments is dangerous; other classes should not do it, and in
case they do, neither should we. So I think the best solution is {code}return o
instanceof List && ((List) o).size() == 2 && Arrays.asList(t0,
t1).equals(o);{code}
> StackOverflowError from FlatList equals()
> -----------------------------------------
>
> Key: CALCITE-2287
> URL: https://issues.apache.org/jira/browse/CALCITE-2287
> Project: Calcite
> Issue Type: Bug
> Reporter: Zhong Yu
> Assignee: Julian Hyde
> Priority: Major
>
> The equals() method of `Flat3List` and `Flat4List` may invoke each other in
> an infinite loop.
> See also https://issues.apache.org/jira/browse/HIVE-18427
>
> We found this problem when such lists are used as keys in
> `RelMetadataQuery.map`; occasionally there are hashcode collisions between
> `Flat3List` and `Flat4List`, hence their equals() methods will be invoked.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
