Fix ractor copy of structs

Author: byroot

ractor.c

@@ -1261,6 +1261,16 @@ obj_traverse_i(VALUE obj, struct obj_traverse_data *data)
             for (long i=0; i<len; i++) {
                 if (obj_traverse_i(ptr[i], data)) return 1;
             }
+
+            if (RSTRUCT_EMBED_LEN(obj)) {
+                if (!FL_TEST_RAW(obj, RSTRUCT_GEN_IVAR_FLAG)) {
+                    if (obj_traverse_i(ptr[len], data)) return 1;
+                }
+            }
+            else {
+                if (obj_traverse_i(RSTRUCT(obj)->as.heap.fields_obj, data)) return 1;
+            }
+
         }
         break;
 
@@ -1681,6 +1691,7 @@ obj_traverse_replace_i(VALUE obj, struct obj_traverse_replace_data *data)
     if (UNLIKELY(rb_obj_exivar_p(obj))) {
         VALUE fields_obj = 0;
         rb_ivar_generic_fields_tbl_lookup(obj, &fields_obj);
+        RUBY_ASSERT(fields_obj);
 
         if (UNLIKELY(rb_shape_obj_too_complex_p(obj))) {
             struct obj_traverse_replace_callback_data d = {

variable.c

@@ -1278,8 +1278,10 @@ rb_free_generic_ivar(VALUE obj)
 
         RB_VM_LOCKING() {
             st_delete(generic_fields_tbl_no_ractor_check(obj), &key, &value);
+            RBASIC_SET_SHAPE_ID(obj, ROOT_SHAPE_ID);
         }
     }
+    RUBY_ASSERT(!rb_obj_exivar_p(obj));
 }
 
 VALUE
@@ -2440,11 +2442,7 @@ rb_copy_generic_ivar(VALUE dest, VALUE obj)
 
     rb_check_frozen(dest);
 
-    if (!rb_obj_exivar_p(obj)) {
-        return;
-    }
-
-    if (rb_gen_fields_tbl_get(obj, 0, &fields_obj)) {
+    if (rb_obj_exivar_p(obj) && rb_gen_fields_tbl_get(obj, 0, &fields_obj)) {
         VALUE new_fields_obj = copy_imemo_fields_ivar(obj, fields_obj, dest);
         if (new_fields_obj) {
             RB_VM_LOCKING() {
@@ -2454,9 +2452,9 @@ rb_copy_generic_ivar(VALUE dest, VALUE obj)
                 RBASIC_SET_SHAPE_ID(dest, RBASIC_SHAPE_ID(new_fields_obj));
             }
         }
-        else {
-            rb_free_generic_ivar(dest);
-        }
+    }
+    else {
+        rb_free_generic_ivar(dest);
     }
 }