Handle running out of shapes in `Object#dup`

There is a handful of call sites where we may transition to
OBJ_TOO_COMPLEX_SHAPE if we just ran out of shapes, but that
weren't handling it properly.

1 files changed, 12 insertions, 10 deletions

diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 2fc9b96114..1e514b7008 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -1382,18 +1382,20 @@ vm_setivar_slowpath(VALUE obj, ID id, VALUE val, const rb_iseq_t *iseq, IVC ic,
         {
             rb_ivar_set(obj, id, val);
             shape_id_t next_shape_id = rb_shape_get_shape_id(obj);
-            rb_shape_t *next_shape = rb_shape_get_shape_by_id(next_shape_id);
-            attr_index_t index;
+            if (next_shape_id != OBJ_TOO_COMPLEX_SHAPE_ID) {
+                rb_shape_t *next_shape = rb_shape_get_shape_by_id(next_shape_id);
+                attr_index_t index;
 
-            if (rb_shape_get_iv_index(next_shape, id, &index)) { // based off the hash stored in the transition tree
-                if (index >= MAX_IVARS) {
-                    rb_raise(rb_eArgError, "too many instance variables");
-                }
+                if (rb_shape_get_iv_index(next_shape, id, &index)) { // based off the hash stored in the transition tree
+                    if (index >= MAX_IVARS) {
+                        rb_raise(rb_eArgError, "too many instance variables");
+                    }
 
-                populate_cache(index, next_shape_id, id, iseq, ic, cc, is_attr);
-            }
-            else {
-                rb_bug("didn't find the id");
+                    populate_cache(index, next_shape_id, id, iseq, ic, cc, is_attr);
+                }
+                else {
+                    rb_bug("didn't find the id");
+                }
             }
 
             return val;