commit 5d14fd7b657c9cc2ece5507b96d47a2a0e5b3e25
author Sundeep Ghuman <sghuman@google.com> Thu Feb 15 14:49:15 2018 -0800
committer Sundeep Ghuman <sghuman@google.com> Thu Feb 15 15:08:15 2018 -0800
tree 8979e44c1f794a29970df665ed79e71d1f411ff0
parent f6965c9c0f6edb210ce7d292d31b91df47d36e61

Safeguard against NPE race condition.

It is possible for the main activity to be quit before the posted
message is executed, safeguard against NPEs in this scenario.

Bug: 73484470
Test: runtest --path frameworks/base/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/AccessPointTest.jav
Change-Id: I34b40089ef2eae213c804e4e379d6ab7825bbceb

packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java

diff --git a/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java b/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java
index b380ac5..c5c1169 100644
--- a/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java
+++ b/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java
@@ -1048,14 +1048,19 @@
         if (newLevel > 0 && newLevel != oldLevel) {
             // Only update labels on visible rssi changes
             updateSpeed();
-            if (mAccessPointListener != null) {
-                ThreadUtils.postOnMainThread(() -> mAccessPointListener.onLevelChanged(this));
-            }
+            ThreadUtils.postOnMainThread(() -> {
+                if (mAccessPointListener != null) {
+                    mAccessPointListener.onLevelChanged(this);
+                }
+            });
+
         }
 
-        if (mAccessPointListener != null) {
-            ThreadUtils.postOnMainThread(() -> mAccessPointListener.onAccessPointChanged(this));
-        }
+        ThreadUtils.postOnMainThread(() -> {
+            if (mAccessPointListener != null) {
+                mAccessPointListener.onAccessPointChanged(this);
+            }
+        });
 
         if (!scanResults.isEmpty()) {
             ScanResult result = scanResults.iterator().next();
@@ -1102,10 +1107,18 @@
             mNetworkInfo = null;
         }
         if (updated && mAccessPointListener != null) {
-            ThreadUtils.postOnMainThread(() -> mAccessPointListener.onAccessPointChanged(this));
+            ThreadUtils.postOnMainThread(() -> {
+                if (mAccessPointListener != null) {
+                    mAccessPointListener.onAccessPointChanged(this);
+                }
+            });
 
             if (oldLevel != getLevel() /* current level */) {
-                ThreadUtils.postOnMainThread(() -> mAccessPointListener.onLevelChanged(this));
+                ThreadUtils.postOnMainThread(() -> {
+                    if (mAccessPointListener != null) {
+                        mAccessPointListener.onLevelChanged(this);
+                    }
+                });
             }
         }
 
@@ -1115,9 +1128,11 @@
     void update(@Nullable WifiConfiguration config) {
         mConfig = config;
         networkId = config != null ? config.networkId : WifiConfiguration.INVALID_NETWORK_ID;
-        if (mAccessPointListener != null) {
-            ThreadUtils.postOnMainThread(() -> mAccessPointListener.onAccessPointChanged(this));
-        }
+        ThreadUtils.postOnMainThread(() -> {
+            if (mAccessPointListener != null) {
+                mAccessPointListener.onAccessPointChanged(this);
+            }
+        });
     }
 
     @VisibleForTesting