From 23fc93a7c1e340e79642d3d0bf4b4658c8645c8e Mon Sep 17 00:00:00 2001
From: Martijn Coenen <maco@google.com>
Date: Mon, 28 Nov 2011 10:43:14 -0800
Subject: [PATCH] Fix NPE on mock NDEF tech operations.

Change-Id: Ib67bd03b6275fdb86a5d6dedc6c7e4fed07ef8b0
---
 core/java/android/nfc/Tag.java       |  7 +++++--
 core/java/android/nfc/tech/Ndef.java | 12 ++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/core/java/android/nfc/Tag.java b/core/java/android/nfc/Tag.java
index a73067a5f7094..9fe0bedfe358c 100644
--- a/core/java/android/nfc/Tag.java
+++ b/core/java/android/nfc/Tag.java
@@ -113,7 +113,7 @@ public final class Tag implements Parcelable {
     /*package*/ final String[] mTechStringList;
     /*package*/ final Bundle[] mTechExtras;
     /*package*/ final int mServiceHandle;  // for use by NFC service, 0 indicates a mock
-    /*package*/ final INfcTag mTagService;
+    /*package*/ final INfcTag mTagService; // interface to NFC service, will be null if mock tag
 
     /*package*/ int mConnectedTechnology;
 
@@ -148,7 +148,7 @@ public final class Tag implements Parcelable {
      * @hide
      */
     public static Tag createMockTag(byte[] id, int[] techList, Bundle[] techListExtras) {
-        // set serviceHandle to 0 to indicate mock tag
+        // set serviceHandle to 0 and tagService to null to indicate mock tag
         return new Tag(id, techList, techListExtras, 0, null);
     }
 
@@ -266,6 +266,9 @@ public final class Tag implements Parcelable {
             throw new IllegalStateException("Close connection to the technology first!");
         }
 
+        if (mTagService == null) {
+            throw new IOException("Mock tags don't support this operation.");
+        }
         try {
             Tag newTag = mTagService.rediscover(getServiceHandle());
             if (newTag != null) {
diff --git a/core/java/android/nfc/tech/Ndef.java b/core/java/android/nfc/tech/Ndef.java
index b266bb6dd1edc..226e079ca226e 100644
--- a/core/java/android/nfc/tech/Ndef.java
+++ b/core/java/android/nfc/tech/Ndef.java
@@ -259,6 +259,9 @@ public final class Ndef extends BasicTagTechnology {
 
         try {
             INfcTag tagService = mTag.getTagService();
+            if (tagService == null) {
+                throw new IOException("Mock tags don't support this operation.");
+            }
             int serviceHandle = mTag.getServiceHandle();
             if (tagService.isNdef(serviceHandle)) {
                 NdefMessage msg = tagService.ndefRead(serviceHandle);
@@ -303,6 +306,9 @@ public final class Ndef extends BasicTagTechnology {
 
         try {
             INfcTag tagService = mTag.getTagService();
+            if (tagService == null) {
+                throw new IOException("Mock tags don't support this operation.");
+            }
             int serviceHandle = mTag.getServiceHandle();
             if (tagService.isNdef(serviceHandle)) {
                 int errorCode = tagService.ndefWrite(serviceHandle, msg);
@@ -335,6 +341,9 @@ public final class Ndef extends BasicTagTechnology {
      */
     public boolean canMakeReadOnly() {
         INfcTag tagService = mTag.getTagService();
+        if (tagService == null) {
+            return false;
+        }
         try {
             return tagService.canMakeReadOnly(mNdefType);
         } catch (RemoteException e) {
@@ -366,6 +375,9 @@ public final class Ndef extends BasicTagTechnology {
 
         try {
             INfcTag tagService = mTag.getTagService();
+            if (tagService == null) {
+                return false;
+            }
             if (tagService.isNdef(mTag.getServiceHandle())) {
                 int errorCode = tagService.ndefMakeReadOnly(mTag.getServiceHandle());
                 switch (errorCode) {