GraphicProducerWrapper may return false transact status

GraphicProducerWrapper(GPW) changed how the methods of
BpGraphicBufferProducer(BpGBP) are executed.
First, "fake" BpGBP is created. Its remote is GPW. The GPW has
wrapped the real BpGBP.
All the method calls to the fake BpGPB will be intercepted by
the GPW inside it when the methods run into remote()->transact().
Then the GPW will invoke the transact() of the real BpGBP. And
Everything runs well except that the GPW forgets to store the
transact status and always return NO_ERROR to the fake BpGBP.

It would be disastrous if the binder call of the IGBP failed and
the out parameter "reply" of transact() was in unkown state.
E.g. the queueBuffer() in the fake BpGBP will try to operate on
the "reply". This will crash the SurfaceFlinger.

Change-Id: I01b31f64e1fc92804da3f16c1fb1420dcfb3b855
Signed-off-by: bdeng3X <bingx.deng@intel.com>
Signed-off-by: Guobin Zhang <guobin.zhang@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index bc559ccf73..943ed02216 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2639,7 +2639,7 @@ class GraphicProducerWrapper : public BBinder, public MessageHandler {
             looper->sendMessage(this, Message(MSG_API_CALL));
             barrier.wait();
         }
-        return NO_ERROR;
+        return result;
     }
 
     /*
@@ -2649,7 +2649,7 @@ class GraphicProducerWrapper : public BBinder, public MessageHandler {
     virtual void handleMessage(const Message& message) {
         android_atomic_release_load(&memoryBarrier);
         if (message.what == MSG_API_CALL) {
-            impl->asBinder()->transact(code, data[0], reply);
+            result = impl->asBinder()->transact(code, data[0], reply);
             barrier.open();
         } else if (message.what == MSG_EXIT) {
             exitRequested = true;