Fix detection of freed emacs_values (Bug#32479)

* src/emacs-module.c (module_free_global_ref): Compare a value to be
freed with all entries of the list.

* test/data/emacs-module/mod-test.c (Fmod_test_globref_free): New
function.
(emacs_module_init): Make it accessible from Lisp.
* test/src/emacs-module-tests.el (mod-test-globref-free-test): New
test which uses it.

2 files changed, 22 insertions, 0 deletions

diff --git a/test/data/emacs-module/mod-test.c b/test/data/emacs-module/mod-test.c
index a1c115f00d2..4c783faeeae 100644
--- a/test/data/emacs-module/mod-test.c
+++ b/test/data/emacs-module/mod-test.c
@@ -156,6 +156,24 @@ Fmod_test_globref_make (emacs_env *env, ptrdiff_t nargs, emacs_value args[],
   return env->make_global_ref (env, lisp_str);
 }
 
+/* Create a few global references from arguments and free them.  */
+static emacs_value
+Fmod_test_globref_free (emacs_env *env, ptrdiff_t nargs, emacs_value args[],
+			void *data)
+{
+  emacs_value refs[10];
+  for (int i = 0; i < 10; i++)
+    {
+      refs[i] = env->make_global_ref (env, args[i % nargs]);
+    }
+  for (int i = 0; i < 10; i++)
+    {
+      env->free_global_ref (env, refs[i]);
+    }
+  return env->intern (env, "ok");
+}
+
+
 
 /* Return a copy of the argument string where every 'a' is replaced
    with 'b'.  */
@@ -339,6 +357,7 @@ emacs_module_init (struct emacs_runtime *ert)
   DEFUN ("mod-test-non-local-exit-funcall", Fmod_test_non_local_exit_funcall,
 	 1, 1, NULL, NULL);
   DEFUN ("mod-test-globref-make", Fmod_test_globref_make, 0, 0, NULL, NULL);
+  DEFUN ("mod-test-globref-free", Fmod_test_globref_free, 4, 4, NULL, NULL);
   DEFUN ("mod-test-string-a-to-b", Fmod_test_string_a_to_b, 1, 1, NULL, NULL);
   DEFUN ("mod-test-userptr-make", Fmod_test_userptr_make, 1, 1, NULL, NULL);
   DEFUN ("mod-test-userptr-get", Fmod_test_userptr_get, 1, 1, NULL, NULL);
diff --git a/test/src/emacs-module-tests.el b/test/src/emacs-module-tests.el
index d9406a9609e..9f598c68275 100644
--- a/test/src/emacs-module-tests.el
+++ b/test/src/emacs-module-tests.el
@@ -136,6 +136,9 @@ changes."
     (garbage-collect) ;; XXX: not enough to really test but it's something..
     (should (string= ref-str mod-str))))
 
+(ert-deftest mod-test-globref-free-test ()
+  (should (eq (mod-test-globref-free 1 'a "test" 'b) 'ok)))
+
 (ert-deftest mod-test-string-a-to-b-test ()
   (should (string= (mod-test-string-a-to-b "aaa") "bbb")))