fix a compile error

core/input_map.cpp

@@ -168,7 +168,7 @@ Array InputMap::_get_action_list(const StringName& p_action) {
 	Array ret;
 	const List<InputEvent> *al = get_action_list(p_action);
 	if (al) {
-		for(List<InputEvent>::Element *E=al->front();E;E=E->next()) {
+		for(const List<InputEvent>::Element *E=al->front();E;E=E->next()) {
 
 			ret.push_back(E->get());;
 		}
@@ -192,7 +192,7 @@ bool InputMap::event_is_action(const InputEvent& p_event, const StringName& p_ac
 
 	Map<StringName,Action >::Element *E=input_map.find(p_action);
 	if(!E) {
-		ERR_EXPLAIN("Request for unexisting InputMap action: "+String(p_action));
+		ERR_EXPLAIN("Request for nonexistent InputMap action: "+String(p_action));
 		ERR_FAIL_COND_V(!E,false);
 	}
 

core/io/resource_format_xml.cpp

@@ -1374,7 +1374,7 @@ Error ResourceInteractiveLoaderXML::poll() {
 		if (res.is_null()) {
 
 			if (ResourceLoader::get_abort_on_missing_resources()) {
-				ERR_EXPLAIN(local_path+":"+itos(get_current_line())+": editor exported unexisting resource at: "+path);
+				ERR_EXPLAIN(local_path+":"+itos(get_current_line())+": editor exported nonexistent resource at: "+path);
 				ERR_FAIL_V(error);
 			} else {
 				ResourceLoader::notify_load_error("Resource Not Found: "+path);
@@ -1433,7 +1433,7 @@ Error ResourceInteractiveLoaderXML::poll() {
 		if (res.is_null()) {
 
 			if (ResourceLoader::get_abort_on_missing_resources()) {
-				ERR_EXPLAIN(local_path+":"+itos(get_current_line())+": <ext_resource> referenced unexisting resource at: "+path);
+				ERR_EXPLAIN(local_path+":"+itos(get_current_line())+": <ext_resource> referenced nonexistent resource at: "+path);
 				ERR_FAIL_V(error);
 			} else {
 				ResourceLoader::notify_load_error("Resource Not Found: "+path);

tools/editor/editor_node.cpp

@@ -2656,7 +2656,7 @@ Error EditorNode::save_optimized_copy(const String& p_scene,const String& p_pres
 		}
 	}
 
-	ERR_EXPLAIN("Preset '"+p_preset+"' references unexisting saver: "+type);
+	ERR_EXPLAIN("Preset '"+p_preset+"' references nonexistent saver: "+type);
 	ERR_FAIL_COND_V(saver.is_null(),ERR_INVALID_DATA);
 
 	List<Variant> keys;