diff --git a/drm/drmserver/DrmManager.cpp b/drm/drmserver/DrmManager.cpp
index 537791c..49df1c8 100644
--- a/drm/drmserver/DrmManager.cpp
+++ b/drm/drmserver/DrmManager.cpp
@@ -117,7 +117,11 @@
 status_t DrmManager::setDrmServiceListener(
             int uniqueId, const sp<IDrmServiceListener>& drmServiceListener) {
     Mutex::Autolock _l(mLock);
-    mServiceListeners.add(uniqueId, drmServiceListener);
+    if (NULL != drmServiceListener.get()) {
+        mServiceListeners.add(uniqueId, drmServiceListener);
+    } else {
+        mServiceListeners.removeItem(uniqueId);
+    }
     return DRM_NO_ERROR;
 }
 
diff --git a/drm/java/android/drm/DrmManagerClient.java b/drm/java/android/drm/DrmManagerClient.java
index 2f54b33..6caf678 100644
--- a/drm/java/android/drm/DrmManagerClient.java
+++ b/drm/java/android/drm/DrmManagerClient.java
@@ -738,26 +738,34 @@
      */
     private String convertUriToPath(Uri uri) {
         String path = null;
-        String scheme = uri.getScheme();
-        if (null == scheme || scheme.equals("") || scheme.equals(ContentResolver.SCHEME_FILE)) {
-            path = uri.getPath();
-        } else if (scheme.equals(ContentResolver.SCHEME_CONTENT)) {
-            String[] projection = new String[] {MediaStore.MediaColumns.DATA};
-            Cursor cursor = null;
-            try {
-                cursor = mContext.getContentResolver().query(uri, projection, null, null, null);
-            } catch (SQLiteException e) {
-                throw new IllegalArgumentException("Given Uri is not formatted in a way " +
-                        "so that it can be found in media store.");
+        if (null != uri) {
+            String scheme = uri.getScheme();
+            if (null == scheme || scheme.equals("") ||
+                    scheme.equals(ContentResolver.SCHEME_FILE)) {
+                path = uri.getPath();
+            } else if (scheme.equals(ContentResolver.SCHEME_CONTENT)) {
+                String[] projection = new String[] {MediaStore.MediaColumns.DATA};
+                Cursor cursor = null;
+                try {
+                    cursor = mContext.getContentResolver().query(uri, projection, null,
+                            null, null);
+                    if (null == cursor || 0 == cursor.getCount() || !cursor.moveToFirst()) {
+                        throw new IllegalArgumentException("Given Uri could not be found" +
+                                " in media store");
+                    }
+                    int pathIndex = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
+                    path = cursor.getString(pathIndex);
+                } catch (SQLiteException e) {
+                    throw new IllegalArgumentException("Given Uri is not formatted in a way " +
+                            "so that it can be found in media store.");
+                } finally {
+                    if (null != cursor) {
+                        cursor.close();
+                    }
+                }
+            } else {
+                throw new IllegalArgumentException("Given Uri scheme is not supported");
             }
-            if (null == cursor || 0 == cursor.getCount() || !cursor.moveToFirst()) {
-                throw new IllegalArgumentException("Given Uri could not be found in media store");
-            }
-            int pathIndex = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
-            path = cursor.getString(pathIndex);
-            cursor.close();
-        } else {
-            throw new IllegalArgumentException("Given Uri scheme is not supported");
         }
         return path;
     }
diff --git a/drm/libdrmframework/DrmManagerClient.cpp b/drm/libdrmframework/DrmManagerClient.cpp
index fa3d52a..8bb00c3 100644
--- a/drm/libdrmframework/DrmManagerClient.cpp
+++ b/drm/libdrmframework/DrmManagerClient.cpp
@@ -31,6 +31,7 @@
 DrmManagerClient::~DrmManagerClient() {
     DrmManagerClientImpl::remove(mUniqueId);
     mDrmManagerClientImpl->removeClient(mUniqueId);
+    mDrmManagerClientImpl->setOnInfoListener(mUniqueId, NULL);
     delete mDrmManagerClientImpl; mDrmManagerClientImpl = NULL;
 }
 
diff --git a/drm/libdrmframework/DrmManagerClientImpl.cpp b/drm/libdrmframework/DrmManagerClientImpl.cpp
index 32fa491..eea312b 100644
--- a/drm/libdrmframework/DrmManagerClientImpl.cpp
+++ b/drm/libdrmframework/DrmManagerClientImpl.cpp
@@ -81,7 +81,8 @@
             int uniqueId, const sp<DrmManagerClient::OnInfoListener>& infoListener) {
     Mutex::Autolock _l(mLock);
     mOnInfoListener = infoListener;
-    return getDrmManagerService()->setDrmServiceListener(uniqueId, this);
+    return getDrmManagerService()->setDrmServiceListener(uniqueId,
+            (NULL != infoListener.get()) ? this : NULL);
 }
 
 status_t DrmManagerClientImpl::installDrmEngine(int uniqueId, const String8& drmEngineFile) {
diff --git a/include/drm/DrmManagerClient.h b/include/drm/DrmManagerClient.h
index 3dbfbe2..004556f 100644
--- a/include/drm/DrmManagerClient.h
+++ b/include/drm/DrmManagerClient.h
@@ -49,6 +49,9 @@
     class OnInfoListener: virtual public RefBase {
 
     public:
+        virtual ~OnInfoListener() {}
+
+    public:
         virtual void onInfo(const DrmInfoEvent& event) = 0;
     };