Dereference of potentially null field

If the field is actually null, then a null pointer dereference will occur. Field, which is statistically checked against null, is dereferenced.
/src/mongo/db/query/optimizer/rewrites/proj_spec_builder.cpp:118: NULL_FIELD 175088 Reading field "_innerBuilder", which is expected to possibly be "nullptr" in "this->_innerBuilder" (checked 6 out of 7 times).
/src/mongo/db/query/optimizer/rewrites/proj_spec_builder.cpp:118: NULL_FIELD 175088 Attempting to access the managed object of an empty smart pointer "this->_innerBuilder".