Redundant first guard in conformStringToMask: both arms subsumed by the reachable-chars guard #53

Unit

src/lib/mut/LibConformString.sol:31-33 vs :43-45.

Violated property

None behaviourally — this is dead code. mask == 0 makes ((1 << max) - 1) & mask == 0 for every max, and max == 0 makes (1 << 0) - 1 == 0, so the second guard reverts with the identical EmptyStringMask() in both cases. The first guard is unreachable as a distinct behaviour.

Repro

Campaign mutant M01 (first guard's mask==0 arm removed) SURVIVED the full 36-test suite as a true equivalent: no input distinguishes the two guards.

Triage framing

Minor cleanup: delete the first guard (gas/size noise only) or keep it for readability with a comment noting the redundancy. Proved-equivalent by mutation, so removal is test-safe.

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