libgui: disallow NULL Fence pointers

This change eliminates the uses of a NULL sp<Fence> indicating that no waiting
is required.  Instead we use a non-NULL but invalid Fence object for which the
wait methods will return immediately.

Bug: 7892871
Change-Id: I5360aebe3090422ef6920d56c99fc4eedc642e48

1 files changed, 1 insertions, 1 deletions

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 99af85736d..1401154d3c 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -298,7 +298,7 @@ void Layer::setAcquireFence(const sp<const DisplayDevice>& hw,
 
     if (layer.getCompositionType() == HWC_OVERLAY) {
         sp<Fence> fence = mSurfaceFlingerConsumer->getCurrentFence();
-        if (fence.get()) {
+        if (fence->isValid()) {
             fenceFd = fence->dup();
             if (fenceFd == -1) {
                 ALOGW("failed to dup layer fence, skipping sync: %d", errno);