Soften bucket dependencies

mods/ITEMS/bucket/depends.txt

@@ -1,2 +1,2 @@
-mcl_core
+mcl_core?
-doc
+doc?

mods/ITEMS/bucket/init.lua

@@ -7,13 +7,18 @@ minetest.register_alias("bucket", "bucket:bucket_empty")
 minetest.register_alias("bucket_water", "bucket:bucket_water")
 minetest.register_alias("bucket_lava", "bucket:bucket_lava")
 
-minetest.register_craft({
+local mod_doc = minetest.get_modpath("doc")
+local mod_mcl_core = minetest.get_modpath("mcl_core")
+
+if mod_mcl_core then
+	minetest.register_craft({
 		output = 'bucket:bucket_empty 1',
 		recipe = {
 			{'mcl_core:iron_ingot', '', 'mcl_core:iron_ingot'},
 			{'', 'mcl_core:iron_ingot', ''},
 		}
-})
+	})
+end
 
 bucket = {}
 bucket.liquids = {}
@@ -110,7 +115,7 @@ function bucket.register_liquid(source, flowing, itemname, inventory_image, name
 						return itemstack
 					end
 					place_liquid(pointed_thing.under, node, source, flowing, fullness)
-					if doc.entry_exists("nodes", source) then
+					if mod_doc and doc.entry_exists("nodes", source) then
 						doc.mark_entry_as_revealed(user:get_player_name(), "nodes", source)
 					end
 				else
@@ -123,7 +128,7 @@ function bucket.register_liquid(source, flowing, itemname, inventory_image, name
 							return itemstack
 						end
 						place_liquid(pointed_thing.above, node, source, flowing, fullness)
-						if doc.entry_exists("nodes", source) then
+						if mod_doc and doc.entry_exists("nodes", source) then
 							doc.mark_entry_as_revealed(user:get_player_name(), "nodes", source)
 						end
 					else
@@ -194,7 +199,7 @@ minetest.register_craftitem("bucket:bucket_empty", {
 			minetest.add_node(pointed_thing.under, {name="air"})
 			sound_take(nn, pointed_thing.under)
 
-			if doc.entry_exists("nodes", nn) then
+			if mod_doc and doc.entry_exists("nodes", nn) then
 				doc.mark_entry_as_revealed(user:get_player_name(), "nodes", nn)
 			end
 
@@ -228,7 +233,8 @@ minetest.register_craftitem("bucket:bucket_empty", {
 	end,
 })
 
-bucket.register_liquid(
+if mod_mcl_ore then
+	bucket.register_liquid(
 		"mcl_core:water_source",
 		"mcl_core:water_flowing",
 		"bucket:bucket_water",
@@ -236,9 +242,9 @@ bucket.register_liquid(
 		"Water Bucket",
 		"A bucket can be used to collect and release liquids. This one is filled with water.",
 		"Right-click on any block to empty the bucket and put a water source on this spot."
-)
+	)
 
-bucket.register_liquid(
+	bucket.register_liquid(
 		"mcl_core:lava_source",
 		"mcl_core:lava_flowing",
 		"bucket:bucket_lava",
@@ -246,7 +252,8 @@ bucket.register_liquid(
 		"Lava Bucket",
 		"A bucket can be used to collect and release liquids. This one is filled with hot lava, safely contained inside. Use with caution.",
 		"Choose a place where you want to empty the bucket, then get in a safe spot somewhere above it. Be prepared to run away when something goes wrong as the lava will soon start to flow after placing. To empty the bucket (which places a lava source), right-click on your chosen place."
-)
+	)
+end
 
 minetest.register_craft({
 	type = "fuel",