Fix issue of losing tab state

Browser makes a backup of tab state when adding visited history and
page finished. When browser is being destroyed at times there could
be an instance where a background load triggers to write state while
the browser is already in cleanup state. This causes to write empty
state that looses the previous saved status .

Change-Id: I760c36e376c816302f8635c8e73d8b3871faf0b4

2 files changed, 14 insertions, 3 deletions

diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index 457b1c47..454b25a8 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -754,6 +754,12 @@ public class Controller
     /* package */ Bundle createSaveState() {
         Bundle saveState = new Bundle();
         mTabControl.saveState(saveState);
+        // This method is called multiple times.Need to
+        // guard against TabControl not having any tabs
+        // during the destroy cycles which looses all the
+        // existing saved information.
+        if (saveState.isEmpty())
+           return null;
         return saveState;
     }
 
diff --git a/src/com/android/browser/CrashRecoveryHandler.java b/src/com/android/browser/CrashRecoveryHandler.java
index bcdf8b03..c02eb075 100644
--- a/src/com/android/browser/CrashRecoveryHandler.java
+++ b/src/com/android/browser/CrashRecoveryHandler.java
@@ -109,7 +109,9 @@ public class CrashRecoveryHandler {
     }
 
     public void backupState() {
-        mForegroundHandler.postDelayed(mCreateState, BACKUP_DELAY);
+        // Only write if we are not already destroyed
+        if (mController.getTabControl() != null)
+            mForegroundHandler.postDelayed(mCreateState, BACKUP_DELAY);
     }
 
     private Runnable mCreateState = new Runnable() {
@@ -118,8 +120,11 @@ public class CrashRecoveryHandler {
         public void run() {
             try {
                 final Bundle state = mController.createSaveState();
-                Message.obtain(mBackgroundHandler, MSG_WRITE_STATE, state)
-                        .sendToTarget();
+                // block write of null values
+                if (state != null && mController.getTabControl() != null) {
+                    Message.obtain(mBackgroundHandler, MSG_WRITE_STATE, state)
+                            .sendToTarget();
+                }
                 // Remove any queued up saves
                 mForegroundHandler.removeCallbacks(mCreateState);
             } catch (Throwable t) {