Mustang - Gravels in mustangV2
In subroutine sed_MUSTANG_comp_tocr_mixsed in mustangV2 (key_MUSTANG_V2), if there is a mesh with only gravels, the suspension is disable (sed_tocr_mixsed=1000.0_rsh).
A trick has been introduct but is not clean, see https://gitlab.inria.fr/croco-ocean/croco/-/blob/dev_2022_mustang/MUSTANG/sed_MUSTANG.F90#L3730
A loop is done from gravels indexes rather than sand but this is not consistant with the rest of the code