Fix some issues with minetest.clear_craft (#8712)

* Fix some issues with minetest.clear_craft

- Fix memory leak
- Fix crafts with an output count not being cleared when clearing by
  input.
- Fix recipe list being reversed when clearing by input.

* Add CraftInput::empty()

3 files changed, 75 insertions, 50 deletions

diff --git a/games/minimal/mods/test/crafting.lua b/games/minimal/mods/test/crafting.lua
new file mode 100644
index 000000000..8964bd25a
--- /dev/null
+++ b/games/minimal/mods/test/crafting.lua
@@ -0,0 +1,71 @@
+local function test_clear_craft()
+	minetest.log("info", "Testing clear_craft")
+	-- Clearing by output
+	minetest.register_craft({
+		output = "foo",
+		recipe = {{"bar"}}
+	})
+	minetest.register_craft({
+		output = "foo 4",
+		recipe = {{"foo", "bar"}}
+	})
+	assert(#minetest.get_all_craft_recipes("foo") == 2)
+	minetest.clear_craft({output="foo"})
+	assert(minetest.get_all_craft_recipes("foo") == nil)
+	-- Clearing by input
+	minetest.register_craft({
+		output = "foo 4",
+		recipe = {{"foo", "bar"}}
+	})
+	assert(#minetest.get_all_craft_recipes("foo") == 1)
+	minetest.clear_craft({recipe={{"foo", "bar"}}})
+	assert(minetest.get_all_craft_recipes("foo") == nil)
+end
+test_clear_craft()
+
+local function test_get_craft_result()
+	minetest.log("info", "test_get_craft_result()")
+	-- normal
+	local input = {
+		method = "normal",
+		width = 2,
+		items = {"", "default:coal_lump", "", "default:stick"}
+	}
+	minetest.log("info", "torch crafting input: "..dump(input))
+	local output, decremented_input = minetest.get_craft_result(input)
+	minetest.log("info", "torch crafting output: "..dump(output))
+	minetest.log("info", "torch crafting decremented input: "..dump(decremented_input))
+	assert(output.item)
+	minetest.log("info", "torch crafting output.item:to_table(): "..dump(output.item:to_table()))
+	assert(output.item:get_name() == "default:torch")
+	assert(output.item:get_count() == 4)
+	-- fuel
+	local input = {
+		method = "fuel",
+		width = 1,
+		items = {"default:coal_lump"}
+	}
+	minetest.log("info", "coal fuel input: "..dump(input))
+	local output, decremented_input = minetest.get_craft_result(input)
+	minetest.log("info", "coal fuel output: "..dump(output))
+	minetest.log("info", "coal fuel decremented input: "..dump(decremented_input))
+	assert(output.time)
+	assert(output.time > 0)
+	-- cook
+	local input = {
+		method = "cooking",
+		width = 1,
+		items = {"default:cobble"}
+	}
+	minetest.log("info", "cobble cooking input: "..dump(output))
+	local output, decremented_input = minetest.get_craft_result(input)
+	minetest.log("info", "cobble cooking output: "..dump(output))
+	minetest.log("info", "cobble cooking decremented input: "..dump(decremented_input))
+	assert(output.time)
+	assert(output.time > 0)
+	assert(output.item)
+	minetest.log("info", "cobble cooking output.item:to_table(): "..dump(output.item:to_table()))
+	assert(output.item:get_name() == "default:stone")
+	assert(output.item:get_count() == 1)
+end
+test_get_craft_result()
diff --git a/games/minimal/mods/test/init.lua b/games/minimal/mods/test/init.lua
index 73fb6e6b5..4e2a51086 100644
--- a/games/minimal/mods/test/init.lua
+++ b/games/minimal/mods/test/init.lua
@@ -9,5 +9,7 @@ pseudo = PseudoRandom(13)
 assert(pseudo:next() == 22290)
 assert(pseudo:next() == 13854)
 
-dofile(minetest.get_modpath("test") .. "/player.lua")
-dofile(minetest.get_modpath("test") .. "/formspec.lua")
+local modpath = minetest.get_modpath("test")
+dofile(modpath .. "/player.lua")
+dofile(modpath .. "/formspec.lua")
+dofile(modpath .. "/crafting.lua")
diff --git a/games/minimal/mods/test/player.lua b/games/minimal/mods/test/player.lua
index e66539eac..563d0d985 100644
--- a/games/minimal/mods/test/player.lua
+++ b/games/minimal/mods/test/player.lua
@@ -74,51 +74,3 @@ local function run_player_tests(player)
 	minetest.chat_send_all("All tests pass!")
 end
 minetest.register_on_joinplayer(run_player_tests)
-
-
-local function test_get_craft_result()
-	minetest.log("info", "test_get_craft_result()")
-	-- normal
-	local input = {
-		method = "normal",
-		width = 2,
-		items = {"", "default:coal_lump", "", "default:stick"}
-	}
-	minetest.log("info", "torch crafting input: "..dump(input))
-	local output, decremented_input = minetest.get_craft_result(input)
-	minetest.log("info", "torch crafting output: "..dump(output))
-	minetest.log("info", "torch crafting decremented input: "..dump(decremented_input))
-	assert(output.item)
-	minetest.log("info", "torch crafting output.item:to_table(): "..dump(output.item:to_table()))
-	assert(output.item:get_name() == "default:torch")
-	assert(output.item:get_count() == 4)
-	-- fuel
-	local input = {
-		method = "fuel",
-		width = 1,
-		items = {"default:coal_lump"}
-	}
-	minetest.log("info", "coal fuel input: "..dump(input))
-	local output, decremented_input = minetest.get_craft_result(input)
-	minetest.log("info", "coal fuel output: "..dump(output))
-	minetest.log("info", "coal fuel decremented input: "..dump(decremented_input))
-	assert(output.time)
-	assert(output.time > 0)
-	-- cook
-	local input = {
-		method = "cooking",
-		width = 1,
-		items = {"default:cobble"}
-	}
-	minetest.log("info", "cobble cooking input: "..dump(output))
-	local output, decremented_input = minetest.get_craft_result(input)
-	minetest.log("info", "cobble cooking output: "..dump(output))
-	minetest.log("info", "cobble cooking decremented input: "..dump(decremented_input))
-	assert(output.time)
-	assert(output.time > 0)
-	assert(output.item)
-	minetest.log("info", "cobble cooking output.item:to_table(): "..dump(output.item:to_table()))
-	assert(output.item:get_name() == "default:stone")
-	assert(output.item:get_count() == 1)
-end
-test_get_craft_result()