fstring_concurrent_set_create: only assert the string has no ivars

The NEWOBJ tracepoint can generate an object_id, that's alright,
what we don't want is actual instance variables.

2 files changed, 1 insertions, 5 deletions

diff --git a/ext/-test-/tracepoint/tracepoint.c b/ext/-test-/tracepoint/tracepoint.c
index 03887b1d5b..7f7aa24662 100644
--- a/ext/-test-/tracepoint/tracepoint.c
+++ b/ext/-test-/tracepoint/tracepoint.c
@@ -92,10 +92,6 @@ static void
 on_newobj_event(VALUE tpval, void *data)
 {
     VALUE obj = rb_tracearg_object(rb_tracearg_from_tracepoint(tpval));
-    if (RB_TYPE_P(obj, T_STRING)) {
-        // Would fail !rb_obj_gen_fields_p(str) assertion in fstring_concurrent_set_create
-        return;
-    }
     if (!rb_objspace_internal_object_p(obj)) rb_obj_id(obj);
 }
 
diff --git a/string.c b/string.c
index 56c83ca2d5..0370fc5d1e 100644
--- a/string.c
+++ b/string.c
@@ -549,7 +549,7 @@ fstring_concurrent_set_create(VALUE str, void *data)
     RUBY_ASSERT(RB_TYPE_P(str, T_STRING));
     RUBY_ASSERT(OBJ_FROZEN(str));
     RUBY_ASSERT(!FL_TEST_RAW(str, STR_FAKESTR));
-    RUBY_ASSERT(!rb_obj_gen_fields_p(str));
+    RUBY_ASSERT(!rb_shape_obj_has_ivars(str));
     RUBY_ASSERT(RBASIC_CLASS(str) == rb_cString);
     RUBY_ASSERT(!rb_objspace_garbage_object_p(str));