Fix an index error in ArenaVectorBase::insertAt #3486
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Because `resize()` sets `usedElements` to its argument, we were accessing `data[usedElements]`, which can be outside of allocated memory depending the internal state, i.e., `allocatedElements`'s value. It is hard to come up with a test case for this because apparently the failure condition depends on the vector's internal state.
aheejin
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kripken
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Jan 14, 2021
Followup to #3486, I wonder if it isn't a little more clear this way, which avoids the confusion of usedElements being changed while we are using it. In general I think it's best to only use usedElements in the most internal methods, and to call size() otherwise.
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Because
resize()setsusedElementsto its argument, we wereaccessing
data[usedElements], which can be outside of allocated memorydepending the internal state, i.e.,
allocatedElements's value.It is hard to come up with a test case for this because apparently the
failure condition depends on the vector's internal state.