Correct review comment: ptr.add(0) on a dangling pointer is not UB

[Copilot]

A previous automated review comment incorrectly claimed that calling .add(0) on a dangling pointer (e.g., from a zero-capacity Vec) is undefined behavior under strict provenance, and suggested adding an early-return guard.

The claim is wrong. The Rust ptr::add documentation explicitly scopes the provenance/in-bounds requirement to non-zero offsets:

"If the computed offset is non-zero, then self must be derived from a pointer to some allocation..."

For add(0), the computed offset is 0 * size_of::<u8>() = 0, so no provenance requirement applies. The existing code in print_strs_array_with_total_len is sound as-is — no fast-path guard is needed.

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[Copilot]

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