[HADOOP-176] comparators of integral writable types are not transitive for inequalities

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.6.0
• Component/s: io

Environment

red hat

• Assignee: Unassigned
• Reporter: Dick King
• Created: 29/Apr/06 06:25
• Updated: 08/Sep/06 21:19
• Resolved: 17/Aug/06 20:42

Description

Consider the following code from IntWritable.java :

public int compare(byte[] b1, int s1, int l1,
byte[] b2, int s2, int l2)

{ int thisValue = readInt(b1, s1); int thatValue = readInt(b2, s2); return thisValue - thatValue; }

If a Java Runtime subtracts 20 from -(2^31 - 10) it gets a huge positive number, not the negative value that the comparator should return.

LongWritable does this right, of course.

That last line should be

return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1));

-dk