Comment 1 for bug 749064

Another problem in 3.9.2-1:

 g++ -DHAVE_CONFIG_H -I. -I. -I../../inc -I/usr/include/mumps_seq -g -O2 -g -O2 -Wall -c IpDebug.cpp -fPIC -DPIC -o .libs/IpDebug.o
In file included from IpJournalist.hpp:15:0,
                 from IpDebug.cpp:12:
IpSmartPtr.hpp: In constructor 'Ipopt::SmartPtr<T>::SmartPtr()':
IpSmartPtr.hpp:340:12: error: 'NULL' was not declared in this scope
IpSmartPtr.hpp: In copy constructor 'Ipopt::SmartPtr<T>::SmartPtr(const Ipopt::SmartPtr<T>&)':
IpSmartPtr.hpp:359:12: error: 'NULL' was not declared in this scope
IpSmartPtr.hpp: In constructor 'Ipopt::SmartPtr<T>::SmartPtr(T*)':
IpSmartPtr.hpp:379:12: error: 'NULL' was not declared in this scope
IpSmartPtr.hpp: In member function 'Ipopt::SmartPtr<U>& Ipopt::SmartPtr<T>::SetFromRawPtr_(T*)':
IpSmartPtr.hpp:475:16: error: 'NULL' was not declared in this scope
IpSmartPtr.hpp: In member function 'void Ipopt::SmartPtr<T>::ReleasePointer_()':
IpSmartPtr.hpp:518:14: error: 'NULL' was not declared in this scope
IpSmartPtr.hpp: In function 'bool Ipopt::IsNull(const Ipopt::SmartPtr<U>&)':
IpSmartPtr.hpp:557:31: error: 'NULL' was not declared in this scope
make[3]: *** [IpDebug.lo] Error 1
make[3]: Leaving directory `/build/buildd/coinor-ipopt-3.9.2/Ipopt/src/Common'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/build/buildd/coinor-ipopt-3.9.2/Ipopt'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/build/buildd/coinor-ipopt-3.9.2'
make: *** [debian/stamp-makefile-build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2