LAFuture.collect crashes when futures are resolved out of order #1453

merged 1 commit into from May 27, 2013

2 participants

Lift Web Framework member

I'm using LAFuture.collect from Lift 3 Snapshot to collect 3 futures into one. It sometimes throws an IndexOutOfBoundsException at me.
The reason is this line:

val vals = new collection.mutable.ArrayBufferBox[T]

which defines the result array. Later, when future 2 is satisfied before future 1 it tries to insert it at a index that does not yet exist, thus throwing the exception.
The fix I found was to pad the array with Empty's and then later in the foreach write a Full into it.

Here's the repl that produces the exception:

scala> new collection.mutable.ArrayBufferInt
res0: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer()

scala> res0.insert(2, 4)
java.lang.IndexOutOfBoundsException: 2

@tuhlmann tuhlmann was assigned May 25, 2013
Lift Web Framework member

Any opinions?

Lift Web Framework member

Ship it

@dpp dpp merged commit 6363f72 into master May 27, 2013
@dpp dpp deleted the uhl_issue_1453 branch May 27, 2013
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