Minimal: Add river water nodes (#5809)

Is a base terrain node needed by any core mapgen with sloping rivers.

games/minimal/mods/default/init.lua

@@ -992,7 +992,6 @@ minetest.register_node("default:cloud", {
 
 minetest.register_node("default:water_flowing", {
 	description = "Water (flowing)",
-	inventory_image = minetest.inventorycube("default_water.png"),
 	drawtype = "flowingliquid",
 	tiles = {"default_water.png"},
 	special_tiles = {
@@ -1001,11 +1000,13 @@ minetest.register_node("default:water_flowing", {
 	},
 	alpha = WATER_ALPHA,
 	paramtype = "light",
+	paramtype2 = "flowingliquid",
 	walkable = false,
 	pointable = false,
 	diggable = false,
 	buildable_to = true,
 	is_ground_content = false,
+	drop = "",
 	drowning = 1,
 	liquidtype = "flowing",
 	liquid_alternative_flowing = "default:water_flowing",
@@ -1017,7 +1018,6 @@ minetest.register_node("default:water_flowing", {
 
 minetest.register_node("default:water_source", {
 	description = "Water",
-	inventory_image = minetest.inventorycube("default_water.png"),
 	drawtype = "liquid",
 	tiles = {"default_water.png"},
 	special_tiles = {
@@ -1031,6 +1031,7 @@ minetest.register_node("default:water_source", {
 	diggable = false,
 	buildable_to = true,
 	is_ground_content = false,
+	drop = "",
 	drowning = 1,
 	liquidtype = "source",
 	liquid_alternative_flowing = "default:water_flowing",
@@ -1040,6 +1041,62 @@ minetest.register_node("default:water_source", {
 	groups = {water = 3, liquid = 3},
 })
 
+minetest.register_node("default:river_water_source", {
+	description = "River Water Source",
+	drawtype = "liquid",
+	tiles = {"default_river_water.png"},
+	special_tiles = {
+		-- New-style water source material (mostly unused)
+		{name = "default_river_water.png", backface_culling = false},
+	},
+	alpha = 160,
+	paramtype = "light",
+	walkable = false,
+	pointable = false,
+	diggable = false,
+	buildable_to = true,
+	is_ground_content = false,
+	drop = "",
+	drowning = 1,
+	liquidtype = "source",
+	liquid_alternative_flowing = "default:river_water_flowing",
+	liquid_alternative_source = "default:river_water_source",
+	liquid_viscosity = 1,
+	liquid_renewable = false,
+	liquid_range = 2,
+	post_effect_color = {a = 103, r = 30, g = 76, b = 90},
+	groups = {water = 3, liquid = 3, puts_out_fire = 1, cools_lava = 1},
+})
+
+minetest.register_node("default:river_water_flowing", {
+	description = "Flowing River Water",
+	drawtype = "flowingliquid",
+	tiles = {"default_river_water.png"},
+	special_tiles = {
+		{name = "default_river_water.png", backface_culling = false},
+		{name = "default_river_water.png", backface_culling = true},
+	},
+	alpha = 160,
+	paramtype = "light",
+	paramtype2 = "flowingliquid",
+	walkable = false,
+	pointable = false,
+	diggable = false,
+	buildable_to = true,
+	is_ground_content = false,
+	drop = "",
+	drowning = 1,
+	liquidtype = "flowing",
+	liquid_alternative_flowing = "default:river_water_flowing",
+	liquid_alternative_source = "default:river_water_source",
+	liquid_viscosity = 1,
+	liquid_renewable = false,
+	liquid_range = 2,
+	post_effect_color = {a = 103, r = 30, g = 76, b = 90},
+	groups = {water = 3, liquid = 3, puts_out_fire = 1,
+		not_in_creative_inventory = 1, cools_lava = 1},
+})
+
 minetest.register_node("default:lava_flowing", {
 	description = "Lava (flowing)",
 	inventory_image = minetest.inventorycube("default_lava.png"),

games/minimal/mods/default/mapgen.lua

@@ -8,6 +8,7 @@ minetest.register_alias("mapgen_dirt", "default:dirt")
 minetest.register_alias("mapgen_dirt_with_grass", "default:dirt_with_grass")
 minetest.register_alias("mapgen_sand", "default:sand")
 minetest.register_alias("mapgen_water_source", "default:water_source")
+minetest.register_alias("mapgen_river_water_source", "default:river_water_source")
 minetest.register_alias("mapgen_lava_source", "default:lava_source")
 minetest.register_alias("mapgen_gravel", "default:gravel")