Method cache: fix refinement entry handling

To invalidate some callable method entries, we replace the entry in the
class. Most types of method entries are on the method table of the
origin class, but refinement entries without an orig_me are housed in
the method table of the class itself. They are there because refinements
take priority over prepended methods.

By unconditionally inserting a copy of the refinement entry into the
origin class, clearing the method cache created situations where there
are refinement entry duplicates in the lookup chain, leading to infinite
loops and other problems.

Update the replacement logic to use the right class that houses the
method entry. Also, be more selective about cache invalidation when
moving refinement entries for prepend. This avoids calling
clear_method_cache_by_id_in_class() before refinement entries are in the
place it expects.

[Bug #17806]

1 files changed, 3 insertions, 1 deletions

diff --git a/class.c b/class.c
index 6784540a9e..9ac2b3ff47 100644
--- a/class.c
+++ b/class.c
@@ -1181,10 +1181,12 @@ cache_clear_refined_method(ID key, VALUE value, void *data)
 {
     rb_method_entry_t *me = (rb_method_entry_t *) value;
 
-    if (me->def->type == VM_METHOD_TYPE_REFINED) {
+    if (me->def->type == VM_METHOD_TYPE_REFINED && me->def->body.refined.orig_me) {
         VALUE klass = (VALUE)data;
         rb_clear_method_cache(klass, me->called_id);
     }
+    // Refined method entries without an orig_me is going to stay in the method
+    // table of klass, like before the move, so no need to clear the cache.
 
     return ID_TABLE_CONTINUE;
 }