3 files changed, 40 insertions, 1 deletions
diff --git a/src/map.cpp b/src/map.cpp
index 641287c3d..30ce064d6 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -829,7 +829,7 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
 		m_transforming_liquid.push_back(iter);
 
 	voxalgo::update_lighting_nodes(this, changed_nodes, modified_blocks);
-
+	env->getScriptIface()->on_liquid_transformed(changed_nodes);
 
 	/* ----------------------------------------------------------------------
 	 * Manage the queue so that it does not grow indefinately
diff --git a/src/script/cpp_api/s_env.cpp b/src/script/cpp_api/s_env.cpp
index c4a39a869..c11de3757 100644
--- a/src/script/cpp_api/s_env.cpp
+++ b/src/script/cpp_api/s_env.cpp
@@ -25,6 +25,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen/mapgen.h"
 #include "lua_api/l_env.h"
 #include "server.h"
+#include "script/common/c_content.h"
+
 
 void ScriptApiEnv::environment_OnGenerated(v3s16 minp, v3s16 maxp,
 	u32 blockseed)
@@ -267,3 +269,35 @@ void ScriptApiEnv::on_emerge_area_completion(
 		luaL_unref(L, LUA_REGISTRYINDEX, state->args_ref);
 	}
 }
+
+void ScriptApiEnv::on_liquid_transformed(
+	const std::vector<std::pair<v3s16, MapNode>> &list)
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	// Get core.registered_on_liquid_transformed
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_on_liquid_transformed");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_remove(L, -2);
+
+	// Skip converting list and calling hook if there are
+	// no registered callbacks.
+	if(lua_objlen(L, -1) < 1) return;
+
+	// Convert the list to a pos array and a node array for lua
+	int index = 1;
+	const NodeDefManager *ndef = getEnv()->getGameDef()->ndef();
+	lua_createtable(L, list.size(), 0);
+	lua_createtable(L, list.size(), 0);
+	for(std::pair<v3s16, MapNode> p : list) {
+		lua_pushnumber(L, index);
+		push_v3s16(L, p.first);
+		lua_rawset(L, -4);
+		lua_pushnumber(L, index++);
+		pushnode(L, p.second, ndef);
+		lua_rawset(L, -3);
+	}
+
+	runCallbacks(2, RUN_CALLBACKS_MODE_FIRST);
+}
+\ No newline at end of file
diff --git a/src/script/cpp_api/s_env.h b/src/script/cpp_api/s_env.h
index 232a08aaf..090858f17 100644
--- a/src/script/cpp_api/s_env.h
+++ b/src/script/cpp_api/s_env.h
@@ -21,6 +21,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "cpp_api/s_base.h"
 #include "irr_v3d.h"
+#include "mapnode.h"
+#include <vector>
 
 class ServerEnvironment;
 struct ScriptCallbackState;
@@ -41,5 +43,8 @@ public:
 	void on_emerge_area_completion(v3s16 blockpos, int action,
 		ScriptCallbackState *state);
 
+	// Called after liquid transform changes
+	void on_liquid_transformed(const std::vector<std::pair<v3s16, MapNode>> &list);
+
 	void initializeEnvironment(ServerEnvironment *env);
 };