Tuple hashCode crashes when tuple contains null

[scabug]

When one of the elements of a tuple is null, attempting to put the tuple in a hash map causes a !NullPointerException. It appears that the hashCode method on tuples does not handle null as a tuple element. I would expect a tuple to return some hash code even one of its elements is null.

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scala> val x = (null, 1)
x: (Null, Int) = (null,1)

scala> val m = new scala.collection.mutable.HashMap[(String, Int), Int]
m: scala.collection.mutable.HashMap[(String, Int),Int] = Map()

scala> m.update(x, 1)
java.lang.NullPointerException
        at scala.runtime.ScalaRunTime$$._hashCode(ScalaRunTime.scala:82)
        at scala.Tuple2.hashCode(Tuple2.scala:17)
        at scala.collection.mutable.HashTable$$class.elemHashCode(HashTable.scala:151)
        at scala.collection.mutable.HashMap.elemHashCode(HashMap.scala:33)
        at scala.collection.mutable.HashTable$$class.findEntry(HashTable.scala:66)
        at scala.collection.mutab...
scala>

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-216?orig=1
Reporter: Ondrej Lhotak (olhotak)
Attachments:

• tuple.diff (created on Oct 8, 2008 7:24:05 PM UTC, 557 bytes)

[scabug]

pbadenski said:
Reversion: still causes an error in Scala 2.7.1 final

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@paulp said:
I don't know if this is still open because there's some subtlety to the fix, but I just attached a patch that fixes this for my definition of fix.

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@dragos said:
We need to check that with Martin today at the meeting. That bug was fixed, then Martin reverted that fix in a bigger commit. We'll see if that was intentional.

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@odersky said:
Milestone 2.7.0 deleted

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@dragos said:
Fixed in r16962.