Small refactoring of save_vlen [skip hazardlib]
Small refactoring of save_vlen [skip hazardlib]


Former-commit-id: c56033d2fcf7891e4f17bd694b349dc180735a87 [formerly 5ad50ddfb1f2828ce174fd9ba9e9dd7b6ce1a123]
Former-commit-id: 162eb21f480b586703eb3bbf83c72085b36f4e46
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine