Correct behavior when ignore_gravity flag is true, fix mob projectile velocity calculation, add missing entity_def lookup

mods/ENTITIES/mcl_mobs/combat.lua

@@ -1242,8 +1242,8 @@ function mob_class:do_states_attack (dtime)
 						owner = self,
 					})
 					ent = arrow:get_luaentity()
+					v = ent.velocity or v
 					ent.switch = 1
-					v = ent.velocity or 1
 
 					-- important for mcl_shields
 					ent._shooter = self.object
@@ -1255,7 +1255,8 @@ function mob_class:do_states_attack (dtime)
 
 				-- offset makes shoot aim accurate
 				local amount = vector.length(vec)
-				vec = vector.multiply(vec, v / vector.length(vec))
+				vec.y = vec.y + self.shoot_offset
+				vec = vector.multiply(vec, v / amount)
 
 				if self.shoot_arrow then
 					vec = vector.normalize(vec)

mods/ITEMS/vl_projectile/init.lua

@@ -21,7 +21,7 @@ function mod.projectile_physics(obj, entity_def, v, a)
 		v = v or obj:get_velocity()
 		a = a or vector.zero()
 
-		if not entity_def.ignore_gravity then
+		if not entity_def._vl_projectile.ignore_gravity then
 			a = a + vector.new(0,-GRAVITY,0)
 		end
 
@@ -372,6 +372,7 @@ function mod.create(entity_id, options)
 		a = vector.zero()
 		v = a
 	end
+	local entity_def = minetest.registered_entities[entity_id]
 	mod.projectile_physics(obj, entity_def, v, a)
 
 	-- Update projectile parameters