Merge branch 'fix-mobj-slidemove' into 'next'

Make sliding against objects actually work (Fixes #400)

Closes #400

See merge request STJr/SRB2!1348

src/p_map.c

@@ -2257,6 +2257,8 @@ boolean P_CheckPosition(mobj_t *thing, fixed_t x, fixed_t y)
 			{
 				if (!P_BlockThingsIterator(bx, by, PIT_CheckThing))
 					blockval = false;
+				else
+					tmhitthing = tmfloorthing;
 				if (P_MobjWasRemoved(tmthing))
 					return false;
 			}