Allow saving to Downloads.

Add column to mark downloads as being writable, and allow documents
to be created under Downloads backend.  Update database when writing
is finished, and generate unique filenames when they already exist.

Check canonical path on incoming _DATA paths.

Bug: 10667164, 10892621, 10893268
Change-Id: I8c203b96ff042a895b58686903fcd07fc755a00f

1 files changed, 9 insertions, 1 deletions

diff --git a/src/com/android/providers/downloads/Helpers.java b/src/com/android/providers/downloads/Helpers.java
index 33205557..aa763de2 100644
--- a/src/com/android/providers/downloads/Helpers.java
+++ b/src/com/android/providers/downloads/Helpers.java
@@ -16,6 +16,8 @@
 
 package com.android.providers.downloads;
 
+import static com.android.providers.downloads.Constants.TAG;
+
 import android.content.Context;
 import android.net.Uri;
 import android.os.Environment;
@@ -342,7 +344,13 @@ public class Helpers {
      * Checks whether the filename looks legitimate
      */
     static boolean isFilenameValid(String filename, File downloadsDataDir) {
-        filename = filename.replaceFirst("/+", "/"); // normalize leading slashes
+        try {
+            filename = new File(filename).getCanonicalPath();
+        } catch (IOException e) {
+            Log.w(TAG, "Failed to resolve canonical path: " + e);
+            return false;
+        }
+
         return filename.startsWith(Environment.getDownloadCacheDirectory().toString())
                 || filename.startsWith(downloadsDataDir.toString())
                 || filename.startsWith(Environment.getExternalStorageDirectory().toString());