Add additional example.

java/ql/test/query-tests/security/CWE-022/semmle/tests/TaintedPath.java

@@ -32,4 +32,17 @@ public class TaintedPath {
             }
         }
     }
+
+    public void sendUserFileGood2(Socket sock, String user) throws IOException {
+        BufferedReader filenameReader = new BufferedReader(new InputStreamReader(sock.getInputStream(), "UTF-8"));
+        String filename = filenameReader.readLine();
+        // GOOD: remove all ".." sequences and path separators from the filename
+        filename = filename.replaceAll("\\.\\.|[/\\\\]", "");
+        BufferedReader fileReader = new BufferedReader(new FileReader(filename));
+        String fileLine = fileReader.readLine();
+        while(fileLine != null) {
+            sock.getOutputStream().write(fileLine.getBytes());
+            fileLine = fileReader.readLine();
+        }
+    }
 }