Fix Namespace.current to show its caller's namespace

Calling rb_current_namespace() in rb_namespace_current() means to show
the definition namespace of Namespace.current itself (it's the root always)
but the users' expectation is to show the namespace of the place where
the Namespace.current is called.

3 files changed, 16 insertions, 6 deletions

diff --git a/eval_intern.h b/eval_intern.h
index 6353319c6f..4ac950e238 100644
--- a/eval_intern.h
+++ b/eval_intern.h
@@ -299,6 +299,7 @@ VALUE rb_vm_call_cfunc(VALUE recv, VALUE (*func)(VALUE), VALUE arg, VALUE block_
 VALUE rb_vm_call_cfunc_in_namespace(VALUE recv, VALUE (*func)(VALUE, VALUE), VALUE arg1, VALUE arg2, VALUE filename, const rb_namespace_t *ns);
 void rb_vm_frame_flag_set_ns_require(const rb_execution_context_t *ec);
 const rb_namespace_t *rb_vm_current_namespace(const rb_execution_context_t *ec);
+const rb_namespace_t *rb_vm_caller_namespace(const rb_execution_context_t *ec);
 const rb_namespace_t *rb_vm_loading_namespace(const rb_execution_context_t *ec);
 void rb_vm_set_progname(VALUE filename);
 VALUE rb_vm_cbase(void);
diff --git a/namespace.c b/namespace.c
index d3ac255363..65a90cb0da 100644
--- a/namespace.c
+++ b/namespace.c
@@ -455,11 +455,12 @@ rb_namespace_s_getenabled(VALUE namespace)
 static VALUE
 rb_namespace_current(VALUE klass)
 {
-    const rb_namespace_t *ns = rb_current_namespace();
+    const rb_namespace_t *ns;
 
     if (!rb_namespace_available())
         return Qnil;
 
+    ns = rb_vm_caller_namespace(GET_EC());
     VM_ASSERT(ns && ns->ns_object);
     return ns->ns_object;
 }
diff --git a/vm.c b/vm.c
index 3eb5d74e83..83119c32d2 100644
--- a/vm.c
+++ b/vm.c
@@ -3052,13 +3052,21 @@ current_namespace_on_env(const VALUE *ep)
 const rb_namespace_t *
 rb_vm_current_namespace(const rb_execution_context_t *ec)
 {
-    const rb_control_frame_t *cfp;
+    VM_ASSERT(rb_namespace_available());
+    return current_namespace_on_env(ec->cfp->ep);
+}
 
-    if (!rb_namespace_available() || !ec)
-        return rb_root_namespace();
+const rb_namespace_t *
+rb_vm_caller_namespace(const rb_execution_context_t *ec)
+{
+    const rb_control_frame_t *caller_cfp;
 
-    cfp = ec->cfp;
-    return current_namespace_on_env(cfp->ep);
+    VM_ASSERT(rb_namespace_available());
+
+    // The current control frame is MAGIC_CFUNC to call Namespace.current, but
+    // we want to get the current namespace of its caller.
+    caller_cfp = vm_get_ruby_level_caller_cfp(ec, RUBY_VM_PREVIOUS_CONTROL_FRAME(ec->cfp));
+    return current_namespace_on_env(caller_cfp->ep);
 }
 
 const rb_namespace_t *