Code review request for 6992121: StringBuilder.ensureCapacity(int minCap) throws OutOfMemoryError

[Mandy Chung]

  Please review the fix for:

6992121: StringBuilder.ensureCapacity(int minCap) throws 
OutOfMemoryError with minCap=Integer.MIN_VALUE

Webrev at:
     http://cr.openjdk.java.net/~mchung/6992121/webrev.00/

This is a regression caused by the changes for 6933217 (Huge arrays 
handled poorly in core libraries).   The ensureCapacity() method in the 
StringBuffer, StringBuilder, ArrayList, and Vector classes are a public 
API that accepts negative numbers.   The following overflow-conscious code:

   if (minimumCapacity - value.length>  0)

considers negative minimumCapacity as overflow case where OutOfMemoryError will be thrown.  So the implementation of the public ensureCapacity() methods need to check if the input argument is positive before doing the above overflow-conscious check.

Thanks
Mandy