{Boolean,Byte,Char,Double,Float,Int,Long,Short}s.concat() may throw {NegativeArraySize,ArrayIndexOutOfBounds}Exception

[ineuwirth]

The concat() method in the per-type primitive utility classes throws unexpected NegativeArraySizeException or ArrayIndexOutOfBoundsException if the input arrays contain too many elements.

NegativeArraySizeException is being thrown if there is an overflow ending up with a negative int. In this case, the result array cannot be constructed with this number.

ArrayIndexOutOfBoundsException is being thrown if there is an overflow ending up with a non-negative int. In this case, the result array will be shorter than expected and System.arraycopy() will throw AIOOBE.

[ineuwirth]

Test cases to demonstrate the issue can be found in #3304.

I am happy to cover other classes and modules (android, gwt) as well if you think the test cases/provided fix are good.

[kluever]

This isn't actually a bug, right? It's just improving the API docs?

[ineuwirth]

Well, a similar issue has been fixed in code instead of documenting the behavior e.g. in #3026.
Also, in case of an overflow ending up with a positive number, we could prevent a potentially big array from being allocated for nothing.