Schematics: Fix minetest.place_schematic() when defined by a Lua table

src/mg_schematic.cpp

@@ -57,7 +57,7 @@ void Schematic::updateContentIds()
 
 	flags |= SCHEM_CIDS_UPDATED;
 
-	for (int i = 0; i != size.X * size.Y * size.Z; i++)
+	for (size_t i = 0; i != size.X * size.Y * size.Z; i++)
 		schemdata[i].setContent(c_nodes[schemdata[i].getContent()]);
 }
 

src/script/common/c_content.cpp

@@ -1098,7 +1098,10 @@ bool read_schematic(lua_State *L, int index, Schematic *schem,
 		}
 	}
 
-	schem->flags       = 0;
+	// Here, we read the nodes directly from the INodeDefManager - there is no
+	// need for pending node resolutions so we'll mark this schematic as updated
+	schem->flags       = SCHEM_CIDS_UPDATED;
+
 	schem->size        = size;
 	schem->schemdata   = schemdata;
 	schem->slice_probs = slice_probs;