  The Josephson supercurrent through the hybrid Majorana--quantum dot--Majorana
junction is investigated. We particularly analyze the effect of spin-selective
coupling between the Majorana and quantum dot states, which emerges only in the
topological phase and will influence the current through bent junctions and/or
in the presence of magnetic fields in the quantum dot. We find that the
characteristic behaviors of the supercurrent through this system are quite
counterintuitive, remarkably differing from the resonant tunneling, e.g.,
through the similar (normal phase) superconductor--quantum dot--superconductor
junction. Our analysis is carried out under the influence of full set-up
parameters and for both the $2\pi$ and $4\pi$ periodic currents. The present
study is expected to be relevant to future exploration of applications of the
Majorana-nanowire circuits.
