Incorrect code completion after pressing return on an 'if() {'

How to reproduce

• Open creator, qmljseditor.cpp
• Paste snippet at the beginning of the file:

  void f(bool a, bool b) {
      if (a
          && b) {
          return;
      }
  }
  

• Place cursor after opening bracket
• Press OK
• Result:

  void f(bool a, bool b) {
      if (a
          && b) {
          
      }
          return;
      }
  }
  

• Expected:

  void f(bool a, bool b) {
      if (a
          && b) {
          
          return;
      }
  }
  

Note that this isn't always reproducable for random files, for whatever reason.