From f4ded970a7437c4c2c064cc7dded94da61b8a8a5 Mon Sep 17 00:00:00 2001
From: Shuo Qian <shuoq@google.com>
Date: Fri, 30 Oct 2020 16:17:14 -0700
Subject: [PATCH] Fix ConcurrentModificationException of getEmergencyNumberList

Test: atest; treehugger
Bug: 171542607
Change-Id: I5812469dfb96f30b5b185fc1bb983e3357bb4efa
---
 .../android/telephony/TelephonyManager.java   | 49 +++++++++++++------
 1 file changed, 34 insertions(+), 15 deletions(-)

diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index e341e0c19cf5f..246429aae25b9 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -12321,23 +12321,15 @@ public class TelephonyManager {
     @NonNull
     public Map<Integer, List<EmergencyNumber>> getEmergencyNumberList(
             @EmergencyServiceCategories int categories) {
-        Map<Integer, List<EmergencyNumber>> emergencyNumberList = new HashMap<>();
+        Map<Integer, List<EmergencyNumber>> emergencyNumberListForCategories = new HashMap<>();
         try {
             ITelephony telephony = getITelephony();
             if (telephony != null) {
-                emergencyNumberList = telephony.getEmergencyNumberList(
-                        mContext.getOpPackageName(), mContext.getAttributionTag());
-                if (emergencyNumberList != null) {
-                    for (Integer subscriptionId : emergencyNumberList.keySet()) {
-                        List<EmergencyNumber> numberList = emergencyNumberList.get(subscriptionId);
-                        for (EmergencyNumber number : numberList) {
-                            if (!number.isInEmergencyServiceCategories(categories)) {
-                                numberList.remove(number);
-                            }
-                        }
-                    }
-                }
-                return emergencyNumberList;
+                Map<Integer, List<EmergencyNumber>> emergencyNumberList =
+                        telephony.getEmergencyNumberList(mContext.getOpPackageName(),
+                                mContext.getAttributionTag());
+                emergencyNumberListForCategories =
+                        filterEmergencyNumbersByCategories(emergencyNumberList, categories);
             } else {
                 throw new IllegalStateException("telephony service is null.");
             }
@@ -12345,7 +12337,34 @@ public class TelephonyManager {
             Log.e(TAG, "getEmergencyNumberList with Categories RemoteException", ex);
             ex.rethrowAsRuntimeException();
         }
-        return emergencyNumberList;
+        return emergencyNumberListForCategories;
+    }
+
+    /**
+     * Filter emergency numbers with categories.
+     *
+     * @hide
+     */
+    @VisibleForTesting
+    public Map<Integer, List<EmergencyNumber>> filterEmergencyNumbersByCategories(
+            Map<Integer, List<EmergencyNumber>> emergencyNumberList,
+                    @EmergencyServiceCategories int categories) {
+        Map<Integer, List<EmergencyNumber>> emergencyNumberListForCategories = new HashMap<>();
+        if (emergencyNumberList != null) {
+            for (Integer subscriptionId : emergencyNumberList.keySet()) {
+                List<EmergencyNumber> allNumbersForSub = emergencyNumberList.get(
+                        subscriptionId);
+                List<EmergencyNumber> numbersForCategoriesPerSub = new ArrayList<>();
+                for (EmergencyNumber number : allNumbersForSub) {
+                    if (number.isInEmergencyServiceCategories(categories)) {
+                        numbersForCategoriesPerSub.add(number);
+                    }
+                }
+                emergencyNumberListForCategories.put(
+                        subscriptionId, numbersForCategoriesPerSub);
+            }
+        }
+        return emergencyNumberListForCategories;
     }
 
     /**