Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ecb3891d authored by Kean Mariotti's avatar Kean Mariotti
Browse files

viewcapture: fix NPE (WindowListener#mRoot) 

WindowListener#onDraw() assumes that mRoot != null which may not be true
when the capture is being stopped, i.e. when a non-UI thread is setting
"mRoot = null" while the UI thread is executing WindowListener#onDraw().

Bug: 391977087
Flag: EXEMPT minor bugfix
Test: check the NPE doesn't happen again on the lab
Change-Id: I6a7c979e1862beb27e204baf30c1d33c93b0c2a5
parent 66f97f4a

viewcapturelib/src/com/android/app/viewcapture/ViewCapture.java

+17 −8
Original line number Diff line number Diff line
@@ -328,7 +328,14 @@ public abstract class ViewCapture { 
        @UiThread

        public void onDraw() {

            Trace.beginSection("vc#onDraw");

            captureViewTree(mRoot, mViewPropertyRef);

            try {

                View root = mRoot;

                if (root == null) {

                    // Handle the corner case where another (non-UI) thread

                    // concurrently stopped the capture and set mRoot = null

                    return;

                }

                captureViewTree(root, mViewPropertyRef);

                ViewPropertyRef captured = mViewPropertyRef.next;

                if (captured != null) {

                    captured.callback = mCaptureCallback;
@@ -336,8 +343,10 @@ public abstract class ViewCapture { 
                    mBgExecutor.execute(captured);

                }

                mIsFirstFrame = false;

            } finally {

                Trace.endSection();

            }

        }



        /**

         * Copy clean views from the last frame on the background thread. Clean views are