lonely eagle
31ddc7e564
When insertColumns does not trigger a physical reallocation, the inner loop needlessly loops up to nReservedColumns - 1. This causes massive redundant zero-writes on trailing columns that are already zero. This patch truncates the inner loop start boundary to nColumns - 1, when the reserved capacity is unchanged, optimizing the non-realloc path from O(nRows * nReservedColumns) to O(nRows * nColumns).