JRuby

Inconsistent == on java.lang.Integer between Mac and RedHat Enterprise Linux

Details

  • Type: Bug Bug
  • Status: Resolved Resolved
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: JRuby 1.6.7
  • Fix Version/s: JRuby 1.7.0.pre2
  • Component/s: None
  • Labels:
    None
  • Number of attachments :
    0

Description

require 'java'

5==java.lang.Integer.new(5) returns true on Macs but nil on linux. I tried this on several different versions of JRuby up to and including 1.6.7.

On the RHEL install and any macs the following returned true
5.0 == java.lang.Double.new(5)
5 == java.lang.Long.new(5)

The fact that only Integer has this issue makes me think its some sort of bug related to JRuby on on Redhat. Id' be willing to try other things or do more investigation but right now I'm not sure how to proceed.

Activity

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Charles Oliver Nutter added a comment -

I would be more inclined to pin this on JVM differences. Sometimes JDK classes will add a new method that takes a primitive, and we'll start picking that one up.

In this case, at least for fixnums, == will flip it around and call == on java.lang.Integer, which will call the Java equals(Object) and should coerce the fixnum to a java.lang.Long.

On master/1.7 this actually leads to a ClassCastException:

system ~/projects/jruby/tmp $ jruby -rjava -e "5 == java.lang.Integer.new(5)"
Integer.java:37:in `compareTo': java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer

On 1.6.7 I see "true" result as you do (on Mac) for all cases, on both Java 6 and Java 7.

I just happen to have a fedora VM here, so I'll give it a shot. Can you tell me what version of Java you tried with?

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Charles Oliver Nutter added a comment - I would be more inclined to pin this on JVM differences. Sometimes JDK classes will add a new method that takes a primitive, and we'll start picking that one up. In this case, at least for fixnums, == will flip it around and call == on java.lang.Integer, which will call the Java equals(Object) and should coerce the fixnum to a java.lang.Long. On master/1.7 this actually leads to a ClassCastException: system ~/projects/jruby/tmp $ jruby -rjava -e "5 == java.lang.Integer.new(5)" Integer.java:37:in `compareTo': java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer On 1.6.7 I see "true" result as you do (on Mac) for all cases, on both Java 6 and Java 7. I just happen to have a fedora VM here, so I'll give it a shot. Can you tell me what version of Java you tried with?
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Charles Oliver Nutter added a comment -

Created JRUBY-6745 to track the ClassCastException.

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Charles Oliver Nutter added a comment - Created JRUBY-6745 to track the ClassCastException.
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Jason Gilman added a comment -

The java version was:
java version "1.6.0_31"
Java(TM) SE Runtime Environment (build 1.6.0_31-b04)
Java HotSpot(TM) 64-Bit Server VM (build 20.6-b01, mixed mode)

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Jason Gilman added a comment - The java version was: java version "1.6.0_31" Java(TM) SE Runtime Environment (build 1.6.0_31-b04) Java HotSpot(TM) 64-Bit Server VM (build 20.6-b01, mixed mode)
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Charles Oliver Nutter added a comment -

Ok, it's very likely what I suspected: subtle differences between the Java installs.

I committed a fix for JRUBY-6745 that also will probably fix this issue by making the selected methods more consistent across platforms. I don't have a RHEL instance set up right now, so can you confirm this for me with a master build?

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Charles Oliver Nutter added a comment - Ok, it's very likely what I suspected: subtle differences between the Java installs. I committed a fix for JRUBY-6745 that also will probably fix this issue by making the selected methods more consistent across platforms. I don't have a RHEL instance set up right now, so can you confirm this for me with a master build?
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Jason Gilman added a comment - - edited

I just cloned and built jruby master on my RHEL instance. I can confirm the bug is fixed now. Thanks for fixing this!

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Jason Gilman added a comment - - edited I just cloned and built jruby master on my RHEL instance. I can confirm the bug is fixed now. Thanks for fixing this!

People

  • Assignee:
    Charles Oliver Nutter
    Reporter:
    Jason Gilman
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  • Created:
    Updated:
    Resolved: