1 files changed, 21 insertions, 5 deletions
diff --git a/src/main/java/eu/siacs/conversations/persistance/FileBackend.java b/src/main/java/eu/siacs/conversations/persistance/FileBackend.java
index 0d770fef..30609214 100644
--- a/src/main/java/eu/siacs/conversations/persistance/FileBackend.java
+++ b/src/main/java/eu/siacs/conversations/persistance/FileBackend.java
@@ -693,13 +693,29 @@ public class FileBackend {
 	}
 
 
-	public static boolean weOwnFile(Uri uri) {
-		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+	public static boolean weOwnFile(Context context, Uri uri) {
+		if (uri == null || !ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
 			return false;
+		} else if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+			return fileIsInFilesDir(context, uri);
 		} else {
-			return uri != null
-					&& ContentResolver.SCHEME_FILE.equals(uri.getScheme())
-					&& weOwnFileLollipop(uri);
+			return weOwnFileLollipop(uri);
+		}
+	}
+
+
+	/**
+	 * This is more than hacky but probably way better than doing nothing
+	 * Further 'optimizations' might contain to get the parents of CacheDir and NoBackupDir
+	 * and check against those as well
+	 */
+	private static boolean fileIsInFilesDir(Context context, Uri uri) {
+		try {
+			final String haystack = context.getFilesDir().getParentFile().getCanonicalPath();
+			final String needle = new File(uri.getPath()).getCanonicalPath();
+			return needle.startsWith(haystack);
+		} catch (IOException e) {
+			return false;
 		}
 	}