diff --git a/core/java/android/content/ContentProvider.java b/core/java/android/content/ContentProvider.java
index cdeaea3..e2c898d 100644
--- a/core/java/android/content/ContentProvider.java
+++ b/core/java/android/content/ContentProvider.java
@@ -54,6 +54,7 @@
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Objects;
 
 /**
  * Content providers are one of the primary building blocks of Android applications, providing
@@ -208,7 +209,7 @@
         @Override
         public Cursor query(String callingPkg, Uri uri, @Nullable String[] projection,
                 @Nullable Bundle queryArgs, @Nullable ICancellationSignal cancellationSignal) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             if (enforceReadPermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
                 // The caller has no access to the data, so return an empty cursor with
@@ -247,14 +248,14 @@
 
         @Override
         public String getType(Uri uri) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             return ContentProvider.this.getType(uri);
         }
 
         @Override
         public Uri insert(String callingPkg, Uri uri, ContentValues initialValues) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             int userId = getUserIdFromUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             if (enforceWritePermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
@@ -270,7 +271,7 @@
 
         @Override
         public int bulkInsert(String callingPkg, Uri uri, ContentValues[] initialValues) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             if (enforceWritePermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
                 return 0;
@@ -292,11 +293,12 @@
             for (int i = 0; i < numOperations; i++) {
                 ContentProviderOperation operation = operations.get(i);
                 Uri uri = operation.getUri();
-                validateIncomingUri(uri);
                 userIds[i] = getUserIdFromUri(uri);
-                if (userIds[i] != UserHandle.USER_CURRENT) {
-                    // Removing the user id from the uri.
-                    operation = new ContentProviderOperation(operation, true);
+                uri = validateIncomingUri(uri);
+                uri = maybeGetUriWithoutUserId(uri);
+                // Rebuild operation if we changed the Uri above
+                if (!Objects.equals(operation.getUri(), uri)) {
+                    operation = new ContentProviderOperation(operation, uri);
                     operations.set(i, operation);
                 }
                 if (operation.isReadOperation()) {
@@ -331,7 +333,7 @@
 
         @Override
         public int delete(String callingPkg, Uri uri, String selection, String[] selectionArgs) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             if (enforceWritePermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
                 return 0;
@@ -347,7 +349,7 @@
         @Override
         public int update(String callingPkg, Uri uri, ContentValues values, String selection,
                 String[] selectionArgs) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             if (enforceWritePermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
                 return 0;
@@ -364,7 +366,7 @@
         public ParcelFileDescriptor openFile(
                 String callingPkg, Uri uri, String mode, ICancellationSignal cancellationSignal,
                 IBinder callerToken) throws FileNotFoundException {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             enforceFilePermission(callingPkg, uri, mode, callerToken);
             final String original = setCallingPackage(callingPkg);
@@ -380,7 +382,7 @@
         public AssetFileDescriptor openAssetFile(
                 String callingPkg, Uri uri, String mode, ICancellationSignal cancellationSignal)
                 throws FileNotFoundException {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             enforceFilePermission(callingPkg, uri, mode, null);
             final String original = setCallingPackage(callingPkg);
@@ -406,7 +408,7 @@
 
         @Override
         public String[] getStreamTypes(Uri uri, String mimeTypeFilter) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             return ContentProvider.this.getStreamTypes(uri, mimeTypeFilter);
         }
@@ -415,7 +417,7 @@
         public AssetFileDescriptor openTypedAssetFile(String callingPkg, Uri uri, String mimeType,
                 Bundle opts, ICancellationSignal cancellationSignal) throws FileNotFoundException {
             Bundle.setDefusable(opts, true);
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = maybeGetUriWithoutUserId(uri);
             enforceFilePermission(callingPkg, uri, "r", null);
             final String original = setCallingPackage(callingPkg);
@@ -434,7 +436,7 @@
 
         @Override
         public Uri canonicalize(String callingPkg, Uri uri) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             int userId = getUserIdFromUri(uri);
             uri = getUriWithoutUserId(uri);
             if (enforceReadPermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
@@ -450,7 +452,7 @@
 
         @Override
         public Uri uncanonicalize(String callingPkg, Uri uri) {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             int userId = getUserIdFromUri(uri);
             uri = getUriWithoutUserId(uri);
             if (enforceReadPermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
@@ -467,7 +469,7 @@
         @Override
         public boolean refresh(String callingPkg, Uri uri, Bundle args,
                 ICancellationSignal cancellationSignal) throws RemoteException {
-            validateIncomingUri(uri);
+            uri = validateIncomingUri(uri);
             uri = getUriWithoutUserId(uri);
             if (enforceReadPermission(callingPkg, uri, null) != AppOpsManager.MODE_ALLOWED) {
                 return false;
@@ -1901,7 +1903,7 @@
          */
         if (mContext == null) {
             mContext = context;
-            if (context != null) {
+            if (context != null && mTransport != null) {
                 mTransport.mAppOpsManager = (AppOpsManager) context.getSystemService(
                         Context.APP_OPS_SERVICE);
             }
@@ -2010,7 +2012,7 @@
     }
 
     /** @hide */
-    private void validateIncomingUri(Uri uri) throws SecurityException {
+    public Uri validateIncomingUri(Uri uri) throws SecurityException {
         String auth = uri.getAuthority();
         if (!mSingleUser) {
             int userId = getUserIdFromAuthority(auth, UserHandle.USER_CURRENT);
@@ -2029,6 +2031,19 @@
             }
             throw new SecurityException(message);
         }
+
+        // Normalize the path by removing any empty path segments, which can be
+        // a source of security issues.
+        final String encodedPath = uri.getEncodedPath();
+        if (encodedPath != null && encodedPath.indexOf("//") != -1) {
+            final Uri normalized = uri.buildUpon()
+                    .encodedPath(encodedPath.replaceAll("//+", "/")).build();
+            Log.w(TAG, "Normalized " + uri + " to " + normalized
+                    + " to avoid possible security issues");
+            return normalized;
+        } else {
+            return uri;
+        }
     }
 
     /** @hide */
diff --git a/core/java/android/content/ContentProviderOperation.java b/core/java/android/content/ContentProviderOperation.java
index 8f3a317..f3914f2 100644
--- a/core/java/android/content/ContentProviderOperation.java
+++ b/core/java/android/content/ContentProviderOperation.java
@@ -94,13 +94,9 @@
     }
 
     /** @hide */
-    public ContentProviderOperation(ContentProviderOperation cpo, boolean removeUserIdFromUri) {
+    public ContentProviderOperation(ContentProviderOperation cpo, Uri withUri) {
         mType = cpo.mType;
-        if (removeUserIdFromUri) {
-            mUri = ContentProvider.getUriWithoutUserId(cpo.mUri);
-        } else {
-            mUri = cpo.mUri;
-        }
+        mUri = withUri;
         mValues = cpo.mValues;
         mSelection = cpo.mSelection;
         mSelectionArgs = cpo.mSelectionArgs;
@@ -110,14 +106,6 @@
         mYieldAllowed = cpo.mYieldAllowed;
     }
 
-    /** @hide */
-    public ContentProviderOperation getWithoutUserIdInUri() {
-        if (ContentProvider.uriHasUserId(mUri)) {
-            return new ContentProviderOperation(this, true);
-        }
-        return this;
-    }
-
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeInt(mType);
         Uri.writeToParcel(dest, mUri);