Fix debugger calling new String().

Used to return an empty string instead of the newly created String.
Requires accompanying jdwp test fix to test String contents.

Bug: 30951794
Change-Id: I27a8e0afcbe7e32a14dd3c394e44b6cd4d3c58f6
Test: mm -j24 run-jdwp-tests-host

1 files changed, 11 insertions, 4 deletions

diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index 2a5198bf01..b4acc27c48 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -4098,10 +4098,17 @@ void Dbg::ExecuteMethodWithoutPendingException(ScopedObjectAccess& soa, DebugInv
     // unless we threw, in which case we return null.
     DCHECK_EQ(JDWP::JT_VOID, result_tag);
     if (exceptionObjectId == 0) {
-      // TODO we could keep the receiver ObjectId in the DebugInvokeReq to avoid looking into the
-      // object registry.
-      result_value = GetObjectRegistry()->Add(pReq->receiver.Read());
-      result_tag = TagFromObject(soa, pReq->receiver.Read());
+      if (m->GetDeclaringClass()->IsStringClass()) {
+        // For string constructors, the new string is remapped to the receiver (stored in ref).
+        mirror::Object* decoded_ref = soa.Self()->DecodeJObject(ref.get());
+        result_value = gRegistry->Add(decoded_ref);
+        result_tag = TagFromObject(soa, decoded_ref);
+      } else {
+        // TODO we could keep the receiver ObjectId in the DebugInvokeReq to avoid looking into the
+        // object registry.
+        result_value = GetObjectRegistry()->Add(pReq->receiver.Read());
+        result_tag = TagFromObject(soa, pReq->receiver.Read());
+      }
     } else {
       result_value = 0;
       result_tag = JDWP::JT_OBJECT;