title: getStringExtra() fails in onActivityResult()
body: <p>I need to transfer additional data from an Intent to the calling activity.
  The base activity does "startActivityForResult()".</p>
  
  <p>The nested activity sets the result and puts additional data in a click-listener:</p>
  
  <pre><code>public void onClick(View v) {
       setResult(LOGIN_RESULT_IN);
       LoginActivity.this.getIntent().putExtra("username", userStr);
       LoginActivity.this.getIntent().putExtra("password", passStr);
  
       LoginActivity.this.finish();
  }
  </code></pre>
  
  <p>The calling activity checks the data with:</p>
  
  <pre><code>protected void onActivityResult(int requestCode, int resultCode, Intent data) {
      preferences.username = data.getStringExtra("username");
      preferences.password = data.getStringExtra("password");
  }
  </code></pre>
  
  <p>however this return always null. Why doesn't it work?</p>