Fix a cts crash around proxy class fields.

org.apache.harmony.tests.java.io.SerializationStressTest4#test_writeObject_Proxy

As the static fields of proxy classes share the dex file indices, they
shouldn't be resolved in the dex cache or else Field::GetArtField()
may return a wrong art field that belong to a different proxy class.

(cherry pick commit a56ce5e267c9744ed99e40ae5cd9b527971e1d63)

Bug: 20557050

Change-Id: If672c0e67bc49e672e34d75ffbe29c65f5a423b9
diff --git a/runtime/proxy_test.cc b/runtime/proxy_test.cc
index b471293..93d1f66 100644
--- a/runtime/proxy_test.cc
+++ b/runtime/proxy_test.cc
@@ -20,6 +20,7 @@
 #include "art_field-inl.h"
 #include "class_linker-inl.h"
 #include "common_compiler_test.h"
+#include "mirror/field-inl.h"
 #include "mirror/method.h"
 #include "scoped_thread_state_change.h"
 
@@ -191,4 +192,53 @@
   EXPECT_FALSE(field->IsPrimitiveType());
 }
 
+// Creates two proxy classes and check the art/mirror fields of their static fields.
+TEST_F(ProxyTest, CheckArtMirrorFieldsOfProxyStaticFields) {
+  ScopedObjectAccess soa(Thread::Current());
+  jobject jclass_loader = LoadDex("Interfaces");
+  StackHandleScope<7> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+
+  Handle<mirror::Class> proxyClass0;
+  Handle<mirror::Class> proxyClass1;
+  {
+    std::vector<mirror::Class*> interfaces;
+    proxyClass0 = hs.NewHandle(GenerateProxyClass(soa, jclass_loader, "$Proxy0", interfaces));
+    proxyClass1 = hs.NewHandle(GenerateProxyClass(soa, jclass_loader, "$Proxy1", interfaces));
+  }
+
+  ASSERT_TRUE(proxyClass0.Get() != nullptr);
+  ASSERT_TRUE(proxyClass0->IsProxyClass());
+  ASSERT_TRUE(proxyClass0->IsInitialized());
+  ASSERT_TRUE(proxyClass1.Get() != nullptr);
+  ASSERT_TRUE(proxyClass1->IsProxyClass());
+  ASSERT_TRUE(proxyClass1->IsInitialized());
+
+  ArtField* static_fields0 = proxyClass0->GetSFields();
+  ASSERT_TRUE(static_fields0 != nullptr);
+  ASSERT_EQ(2u, proxyClass0->NumStaticFields());
+  ArtField* static_fields1 = proxyClass1->GetSFields();
+  ASSERT_TRUE(static_fields1 != nullptr);
+  ASSERT_EQ(2u, proxyClass1->NumStaticFields());
+
+  EXPECT_EQ(static_fields0[0].GetDeclaringClass(), proxyClass0.Get());
+  EXPECT_EQ(static_fields0[1].GetDeclaringClass(), proxyClass0.Get());
+  EXPECT_EQ(static_fields1[0].GetDeclaringClass(), proxyClass1.Get());
+  EXPECT_EQ(static_fields1[1].GetDeclaringClass(), proxyClass1.Get());
+
+  Handle<mirror::Field> field00 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields0[0], true));
+  Handle<mirror::Field> field01 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields0[1], true));
+  Handle<mirror::Field> field10 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields1[0], true));
+  Handle<mirror::Field> field11 =
+      hs.NewHandle(mirror::Field::CreateFromArtField(soa.Self(), &static_fields1[1], true));
+  EXPECT_EQ(field00->GetArtField(), &static_fields0[0]);
+  EXPECT_EQ(field01->GetArtField(), &static_fields0[1]);
+  EXPECT_EQ(field10->GetArtField(), &static_fields1[0]);
+  EXPECT_EQ(field11->GetArtField(), &static_fields1[1]);
+}
+
 }  // namespace art