From 42b9631ce15660c5c428d50cb4ec77b16eaab155 Mon Sep 17 00:00:00 2001
From: Kevin Ushey <kevinushey@gmail.com>
Date: Mon, 3 Aug 2026 13:35:13 -0700
Subject: [PATCH] convert c++ exceptions to r errors in module .External entry
 points

---
 ChangeLog                   | 10 ++++++++++
 inst/tinytest/test_module.R |  6 ++++++
 src/module.cpp              | 10 +++++++++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 15cefd8f8..a45c14530 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2026-08-03  Kevin Ushey  <kevinushey@gmail.com>
+
+	* src/module.cpp (class__newInstance, CppMethod__invoke,
+	CppMethod__invoke_void, CppMethod__invoke_notvoid): Convert C++
+	exceptions to R errors at these .External entry points, so that
+	e.g. calling a method on an uninitialized module object raises
+	the intended R error rather than terminating the R session
+	(#1495)
+	* inst/tinytest/test_module.R: Add regression test
+
 2026-07-24  Dirk Eddelbuettel  <edd@debian.org>
 
 	* DESCRIPTION (Version, Date): Roll micro version and date
diff --git a/inst/tinytest/test_module.R b/inst/tinytest/test_module.R
index 960a33e96..f9e975bbe 100644
--- a/inst/tinytest/test_module.R
+++ b/inst/tinytest/test_module.R
@@ -102,6 +102,12 @@ x10 <- runif(10, 10.0, 20.0)
 set.seed(123)
 expect_equal(r$get(10), x10)
 
+## calling a method on an uninitialized module object (created via the
+## dummy-object path for classes without a default constructor) should
+## raise an R error rather than terminating the R session (#1495)
+r <- new( ModuleRandomizer )
+expect_error( r$get(10L), "not initialized" )
+
 #    test.Module.flexible.semantics <- function( ){
 expect_equal( test_reference( seq(0,10) ), 11L )
 expect_equal( test_const_reference( seq(0,10) ), 11L )
diff --git a/src/module.cpp b/src/module.cpp
index 3ffb5639b..d90d81ffb 100644
--- a/src/module.cpp
+++ b/src/module.cpp
@@ -135,12 +135,14 @@ END_RCPP
 }														// #nocov end
 
 SEXP class__newInstance(SEXP args) {
+BEGIN_RCPP
     SEXP p = CDR(args);
 
     XP_Module module(CAR(p)); p = CDR(p);
     XP_Class clazz(CAR(p)); p = CDR(p);
     UNPACK_EXTERNAL_ARGS(cargs,p)
     return clazz->newInstance(cargs, nargs);
+END_RCPP
 }
 
 // relies on being set in .onLoad()
@@ -164,6 +166,7 @@ SEXP class__dummyInstance(SEXP args) {
 }
 
 SEXP CppMethod__invoke(SEXP args) {						// #nocov start
+BEGIN_RCPP
     SEXP p = CDR(args);
 
     // the external pointer to the class
@@ -180,9 +183,11 @@ SEXP CppMethod__invoke(SEXP args) {						// #nocov start
     UNPACK_EXTERNAL_ARGS(cargs,p)
 
     return clazz->invoke(met, obj, cargs, nargs);
-}														// #nocov end 
+END_RCPP
+}														// #nocov end
 
 SEXP CppMethod__invoke_void(SEXP args) {
+BEGIN_RCPP
     SEXP p = CDR(args);
 
     // the external pointer to the class
@@ -199,9 +204,11 @@ SEXP CppMethod__invoke_void(SEXP args) {
     UNPACK_EXTERNAL_ARGS(cargs,p)
     clazz->invoke_void(met, obj, cargs, nargs);
     return R_NilValue;
+END_RCPP
 }
 
 SEXP CppMethod__invoke_notvoid(SEXP args) {
+BEGIN_RCPP
     SEXP p = CDR(args);
 
     // the external pointer to the class
@@ -218,6 +225,7 @@ SEXP CppMethod__invoke_notvoid(SEXP args) {
     UNPACK_EXTERNAL_ARGS(cargs,p)
 
     return clazz->invoke_notvoid(met, obj, cargs, nargs);
+END_RCPP
 }
 
 namespace Rcpp{