diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index e8cffa9..297cd7a 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -1360,7 +1360,7 @@
         }
 
         log("No modify permission, check carrier privilege next.");
-        if (hasCarrierPrivileges() != TelephonyManager.CARRIER_PRIVILEGE_STATUS_HAS_ACCESS) {
+        if (getCarrierPrivilegeStatus() != TelephonyManager.CARRIER_PRIVILEGE_STATUS_HAS_ACCESS) {
             loge("No Carrier Privilege.");
             throw new SecurityException("No modify permission or carrier privilege.");
         }
@@ -1372,7 +1372,7 @@
      * @throws SecurityException if the caller does not have the required permission
      */
     private void enforceCarrierPrivilege() {
-        if (hasCarrierPrivileges() != TelephonyManager.CARRIER_PRIVILEGE_STATUS_HAS_ACCESS) {
+        if (getCarrierPrivilegeStatus() != TelephonyManager.CARRIER_PRIVILEGE_STATUS_HAS_ACCESS) {
             loge("No Carrier Privilege.");
             throw new SecurityException("No Carrier Privilege.");
         }
@@ -1497,7 +1497,7 @@
      */
     @Override
     public boolean setVoiceMailNumber(int subId, String alphaTag, String number) {
-        enforceModifyPermissionOrCarrierPrivilege();
+        enforceCarrierPrivilege();
         Boolean success = (Boolean) sendRequest(CMD_SET_VOICEMAIL_NUMBER,
                 new Pair<String, String>(alphaTag, number), new Integer(subId));
         return success;
@@ -1928,10 +1928,10 @@
     }
 
     @Override
-    public int hasCarrierPrivileges() {
+    public int getCarrierPrivilegeStatus() {
         UiccCard card = UiccController.getInstance().getUiccCard();
         if (card == null) {
-            loge("hasCarrierPrivileges: No UICC");
+            loge("getCarrierPrivilegeStatus: No UICC");
             return TelephonyManager.CARRIER_PRIVILEGE_STATUS_RULES_NOT_LOADED;
         }
         return card.getCarrierPrivilegeStatusForCurrentTransaction(
@@ -1975,7 +1975,7 @@
 
     @Override
     public void setLine1NumberForDisplayForSubscriber(int subId, String alphaTag, String number) {
-        enforceModifyPermissionOrCarrierPrivilege();
+        enforceCarrierPrivilege();
 
         String iccId = getIccId(subId);
         if (iccId != null) {
@@ -2023,7 +2023,7 @@
 
     @Override
     public boolean setOperatorBrandOverride(String brand) {
-        enforceModifyPermissionOrCarrierPrivilege();
+        enforceCarrierPrivilege();
         return mPhone.setOperatorBrandOverride(brand);
     }
 
diff --git a/src/com/android/phone/settings/PhoneAccountSettingsFragment.java b/src/com/android/phone/settings/PhoneAccountSettingsFragment.java
index a99c5f0..784be0f 100644
--- a/src/com/android/phone/settings/PhoneAccountSettingsFragment.java
+++ b/src/com/android/phone/settings/PhoneAccountSettingsFragment.java
@@ -50,7 +50,6 @@
     private String LOG_TAG = PhoneAccountSettingsFragment.class.getSimpleName();
 
     private TelecomManager mTelecomManager;
-    private Context mApplicationContext;
 
     private PreferenceCategory mAccountList;
 
@@ -67,7 +66,6 @@
         super.onCreate(icicle);
 
         mTelecomManager = TelecomManager.from(getActivity());
-        mApplicationContext = getActivity().getApplicationContext();
     }
 
     @Override
@@ -243,13 +241,19 @@
     }
 
     private synchronized void handleSipReceiveCallsOption(boolean isEnabled) {
+        Context context = getActivity();
+        if (context == null) {
+            // Return if the fragment is detached from parent activity before executed by thread.
+            return;
+        }
+
         mSipSharedPreferences.setReceivingCallsEnabled(isEnabled);
 
-        SipUtil.useSipToReceiveIncomingCalls(mApplicationContext, isEnabled);
+        SipUtil.useSipToReceiveIncomingCalls(context, isEnabled);
 
         // Restart all Sip services to ensure we reflect whether we are receiving calls.
         SipAccountRegistry sipAccountRegistry = SipAccountRegistry.getInstance();
-        sipAccountRegistry.restartSipService(mApplicationContext);
+        sipAccountRegistry.restartSipService(context);
     }
 
     /**
@@ -303,7 +307,7 @@
             intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
             SubscriptionInfoHelper.addExtrasToIntent(intent, subscription);
 
-            Preference accountPreference = new Preference(mApplicationContext);
+            Preference accountPreference = new Preference(getActivity());
             accountPreference.setTitle(label);
             accountPreference.setIntent(intent);
             mAccountList.addPreference(accountPreference);