Disposable::GetHashCode() throws overflow exception on Int64

[gregboone]

Calling the managed interface function "Disposable::GetHashCode()" can result in an overflow exception if the internal pointer is larger than Int32.

svn diff ...\Fdo\Managed\Src\OSGeo\Runtime\Disposable.cpp

System::Int32 NAMESPACE_OSGEO_RUNTIME::Disposable::GetHashCode() {

• return m_imp.ToInt32();

+ Solution for overflow issue taken from: + ​http://msdn.microsoft.com/en-us/library/system.object.gethashcode(v=vs.71).aspx + + System::Int64 i64 = m_imp.ToInt64(); + return ((System::Int32)(i64) ^{(System::Int32)(i64 >> 32));}

}