Baseline checked on 2026-02-22:

• development: 98bce0678fe1129b3df19e558c0fb21350e5f0b0 (2026-02-21)
• release 26.02: 33007cb7d8798b53082323275ae70ead3e1e9ffa (2026-02-02)

In 1D overset smoothers, masked branch zeroes phi(i,0,0) without component index n:

• Src/LinearSolvers/MLMG/AMReX_MLABecLap_1D_K.H:134 (abec_gsrb_os)
• Src/LinearSolvers/MLMG/AMReX_MLABecLap_1D_K.H:202 (abec_jacobi_os)

Current code:

phi(i,0,0) = T(0.0);

Expected:

phi(i,0,0,n) = T(0.0);

2D/3D overset counterparts already include n.

Trigger

• 1D
• overset path active
• ncomp > 1

Impact

Masked-cell zeroing always writes component 0, leaving other components stale.