Fix ListOf inheritance and compatibility of NamesProxy (#1464)

* fix ListOf inheritance

* update ChangeLog

* Refine NamesProxy setter to set only non-NULL values

* allow name removal

* complete test cases for setting NamesProxy

---------

Co-authored-by: Dirk Eddelbuettel <edd@debian.org>

Author: Enchufa2

ChangeLog

@@ -8,6 +8,14 @@
 
 	* inst/include/Rcpp/Function.h: Further refinement for 4.6.0 to not
 	require R_NamespaceRegistry, using R_getRegisteredNamespace() instead
+2026-04-06  Iñaki Ucar <iucar@fedoraproject.org>
+
+	* inst/tinytest/test_vector.R: Complete test cases for setting NamesProxy
+	* inst/tinytest/cpp/Vector.cpp: Idem
+
+2026-04-03  Dirk Eddelbuettel  <edd@debian.org>
+
+	* inst/include/Rcpp/proxy/NamesProxy.h (set): Only set non-null values
 
 2026-04-01  Mattias Ellert  <mattias.ellert@physics.uu.se>
 
@@ -34,6 +42,10 @@
 	invalid pointer for empty vectors, which causes UB in e.g. std::copy
 	* inst/tinytest/test_vector.R: Add tests for std::copy
 	* inst/tinytest/cpp/Vector.cpp: Idem
+2026-03-27  Iñaki Ucar <iucar@fedoraproject.org>
+
+	* inst/include/Rcpp/vector/ListOf.h: Fix inheritance
+	* inst/include/Rcpp/proxy/NamesProxy.h: Fix compatibility
 
 2026-03-26  Dirk Eddelbuettel  <edd@debian.org>
 

inst/include/Rcpp/proxy/NamesProxy.h

@@ -1,4 +1,5 @@
-// Copyright (C) 2013 Romain Francois
+// Copyright (C) 2013 - 2025  Romain François
+// Copyright (C) 2026         Romain François, Iñaki Ucar and Dirk Eddelbuettel
 //
 // This file is part of Rcpp.
 //
@@ -43,23 +44,13 @@ class NamesProxyPolicy{
         CLASS& parent;
 
         SEXP get() const {
-            return RCPP_GET_NAMES(parent.get__()) ;
+            return RCPP_GET_NAMES(parent) ;
         }
 
         void set(SEXP x) {
-            Shield<SEXP> safe_x(x);
-
-            /* check if we can use a fast version */
-            if( TYPEOF(x) == STRSXP && parent.size() == Rf_length(x) ){		// #nocov start
-                Rf_namesgets(parent, x);
-            } else {
-                /* use the slower and more flexible version (callback to R) */
-                SEXP namesSym = Rf_install( "names<-" );
-                Shield<SEXP> call(Rf_lang3(namesSym, parent, x));
-                Shield<SEXP> new_vec(Rcpp_fast_eval(call, R_GlobalEnv));
-                parent.set__(new_vec);										// #nocov end
-            }
-
+            if (!Rf_isNull(x))
+               Rf_namesgets(parent, x);
+            else Rf_setAttrib(parent, R_NamesSymbol, x);
         }
 
     } ;
@@ -74,7 +65,7 @@ class NamesProxyPolicy{
         const CLASS& parent;
 
         SEXP get() const {
-            return RCPP_GET_NAMES(parent.get__()) ;
+            return RCPP_GET_NAMES(parent) ;
         }
 
     } ;

inst/include/Rcpp/vector/ListOf.h

@@ -1,6 +1,7 @@
 // ListOf.h: Rcpp R/C++ interface class library -- templated List container
 //
-// Copyright (C) 2014 Dirk Eddelbuettel, Romain Francois and Kevin Ushey
+// Copyright (C) 2014 - 2025  Dirk Eddelbuettel, Romain François and Kevin Ushey
+// Copyright (C) 2026         Dirk Eddelbuettel, Romain François, Kevin Ushey and Iñaki Ucar
 //
 // This file is part of Rcpp.
 //
@@ -24,9 +25,9 @@ namespace Rcpp {
 
 template <typename T>
 class ListOf
-    : public NamesProxyPolicy<T>
-    , public AttributeProxyPolicy<T>
-    , public RObjectMethods<T>
+    : public NamesProxyPolicy<ListOf<T>>
+    , public AttributeProxyPolicy<ListOf<T>>
+    , public RObjectMethods<ListOf<T>>
 {
 
 public:

inst/tinytest/cpp/Vector.cpp

@@ -171,11 +171,7 @@ IntegerVector integer_range_ctor_2(){
 }
 
 // [[Rcpp::export]]
-IntegerVector integer_names_set(){
-    IntegerVector y(2) ;
-    std::vector<std::string> names(2)  ;
-    names[0] = "foo" ;
-    names[1] = "bar" ;
+IntegerVector integer_names_set(IntegerVector y, SEXP names) {
     y.names() = names ;
     return y ;
 }

inst/tinytest/test_vector.R

@@ -118,7 +118,10 @@ expect_equal( fun(), 0:3, info = "assign(int*, int*)" )
 
 #    test.IntegerVector.names.set <- function(){
 fun <- integer_names_set
-expect_equal(names(fun()), c("foo", "bar"), info = "Vector::names" )
+x <- 1:2
+expect_equal(names(fun(x, c("foo", "bar"))), c("foo", "bar"), info = "Vector::names set" )
+expect_equal(names(fun(x, "foo")), c("foo", NA), info = "Vector::names set shorter" )
+expect_equal(names(fun(x, NULL)), NULL, info = "Vector::names unset" )
 
 #    test.IntegerVector.names.get <- function(){
 fun <- integer_names_get