avoids issue in routine compute_tgt_field

src/core/interpolation_utils.h

@@ -174,7 +174,7 @@ static inline void compute_tgt_field(
         { \
           YAC_OMP_FOR \
           for (size_t k = 0; k < tgt_count; ++k) { \
-            if (src_frac_masks[i][j][k] != 0.0) \
+            if (fabs(src_frac_masks[i][j][k]) > FRAC_MASK_TOL) \
               tgt_field[i * num_src_fields + j][k] = \
                 SCALE( \
                   tgt_field[i * num_src_fields + j][k] / \