Revert "Revert "Fix issue with proxy invocation on default methods""

This reverts commit daf58c80d42f024aae0cb94ebd2c0bd61ebbf240.

Bug: 27621360
Change-Id: I56fccf19ae80451be4c316ba14911c667cbe9e47

1 files changed, 11 insertions, 3 deletions

diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 3c69323b20..d0a784dfc9 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -4265,10 +4265,18 @@ void ClassLinker::CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prot
   DCHECK(out != nullptr);
   out->CopyFrom(prototype, image_pointer_size_);
 
-  // Set class to be the concrete proxy class and clear the abstract flag, modify exceptions to
-  // the intersection of throw exceptions as defined in Proxy
+  // Set class to be the concrete proxy class.
   out->SetDeclaringClass(klass.Get());
-  out->SetAccessFlags((out->GetAccessFlags() & ~kAccAbstract) | kAccFinal);
+  // Clear the abstract, default and conflict flags to ensure that defaults aren't picked in
+  // preference to the invocation handler.
+  const uint32_t kRemoveFlags = kAccAbstract | kAccDefault | kAccDefaultConflict;
+  // Make the method final.
+  const uint32_t kAddFlags = kAccFinal;
+  out->SetAccessFlags((out->GetAccessFlags() & ~kRemoveFlags) | kAddFlags);
+
+  // Clear the dex_code_item_offset_. It needs to be 0 since proxy methods have no CodeItems but the
+  // method they copy might (if it's a default method).
+  out->SetCodeItemOffset(0);
 
   // At runtime the method looks like a reference and argument saving method, clone the code
   // related parameters from this method.