How to fix this crack + dent on bottom?

I have this small crack and pressure dent on the bottom. Finger nails do catch. What's worrisome is
(1) some "white" stuff can be seen along the crack - that's salt water?
(2) There are a couple of darker spots near the area, I am not sure if those are simply pigment applications or water has leaked into it.
Pictures below:
(1) some "white" stuff can be seen along the crack - that's salt water?
(2) There are a couple of darker spots near the area, I am not sure if those are simply pigment applications or water has leaked into it.
Pictures below: