[sensorservice] Fix on-change sensor send latest value on enable

This CL correct the behavior of sensorservice so that the latest
value of on-change sensor is send to client when enabling sensor.

The errornous behavior before is that sensorservice send the oldest
value in local cache.

Bug: 28480791
Change-Id: I7e0b8e52fa0be62ba95910789cff1fe0d4fbb03f

1 files changed, 2 insertions, 1 deletions

diff --git a/services/sensorservice/RecentEventLogger.cpp b/services/sensorservice/RecentEventLogger.cpp
index dba7211192..754b60393d 100644
--- a/services/sensorservice/RecentEventLogger.cpp
+++ b/services/sensorservice/RecentEventLogger.cpp
@@ -76,7 +76,8 @@ bool RecentEventLogger::populateLastEvent(sensors_event_t *event) const {
     std::lock_guard<std::mutex> lk(mLock);
 
     if (mRecentEvents.size()) {
-        *event = mRecentEvents[mRecentEvents.size()-1].mEvent;
+        // Index 0 contains the latest event emplace()'ed
+        *event = mRecentEvents[0].mEvent;
         return true;
     } else {
         return false;