...at least with both gcc-6.1.1-3.fc24.x86_64 and a recent GCC 7 trunk build it
produces lots of incomprehensible (potentially false positive) occurrences in a
--disable-debug build, like

> [CXX] store/source/stordir.cxx
> In file included from /home/sbergman/lo/core/store/source/stordir.hxx:30:0,
>                  from /home/sbergman/lo/core/store/source/stordir.cxx:20:
> /home/sbergman/lo/core/store/source/storbase.hxx: In member function ‘storeError store::OStoreDirectory_Impl::create(store::OStorePageManager*, rtl_String*, rtl_String*, storeAccessMode)’:
> /home/sbergman/lo/core/store/source/storbase.hxx:237:23: error: potential null pointer dereference [-Werror=null-dereference]
>          m_nUsed = rhs.m_nUsed;
>                    ~~~~^~~~~~~
> /home/sbergman/lo/core/store/source/storbase.hxx:236:23: error: potential null pointer dereference [-Werror=null-dereference]
>          m_nSize = rhs.m_nSize;
>                    ~~~~^~~~~~~
> /home/sbergman/lo/core/store/source/storbase.hxx:235:23: error: potential null pointer dereference [-Werror=null-dereference]
>          m_nAddr = rhs.m_nAddr;
>                    ~~~~^~~~~~~
> [...]
> [CXX] store/source/storlckb.cxx
> In file included from /home/sbergman/lo/core/store/source/storlckb.hxx:29:0,
>                  from /home/sbergman/lo/core/store/source/storlckb.cxx:20:
> /home/sbergman/lo/core/store/source/storbase.hxx: In member function ‘storeError store::OStoreLockBytes::readAt(sal_uInt32, void*, sal_uInt32, sal_uInt32&)’:
> /home/sbergman/lo/core/store/source/storbase.hxx:595:26: error: potential null pointer dereference [-Werror=null-dereference]
>          return isA<U>(p) ? static_cast<U*>(p) : 0;
>                 ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=16351> "NULL dereference warnings"
looks like this is a known problem.

Change-Id: I5eb0c9def7dd12e3a440d280e3fa2331317031b4