title: Validator error message changes TextFormField's height
body: <p>When the error message shows up, it reduces the height of the <code>TextFormField</code>. If I understood correctly, that's because the height of the error message is taking into account in the height specified.</p>
  
  <p>Here's a screen before :</p>
  
  <p><a href="https://i.stack.imgur.com/flgRn.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/flgRn.jpg" alt="before"></a></p>
  
  <p>and after :</p>
  
  <p><a href="https://i.stack.imgur.com/3rxi2.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/3rxi2.jpg" alt="after"></a></p>
  
  <p>Tried to put <code>conterText: ' '</code> to the BoxDecoration (as I've seen on another topic) but it didn't help.</p>
  
  <p>An idea ?</p>
  
  <p>EDIT : OMG completly forgot to put the code, here it is :</p>
  
  <pre class="lang-dart prettyprint-override"><code> return Form(
        key: _formKey,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: &lt;Widget&gt;[
            Container(
              height: 40.0,
              child: _createTextFormField(loginEmailController, Icons.alternate_email, "Email Adress", false, TextInputType.emailAddress),
            ),
            Container(
              height: 40.0,
              child: _createTextFormField(loginPasswordController, Icons.lock, "Password", true, TextInputType.text),
            ),
  
            SizedBox(
              width: double.infinity,
              child: loginButton
            )
          ],
        ),
      );
  
    }
  
    Widget _createTextFormField(TextEditingController controller, IconData icon, String hintText, bool obscureText, TextInputType inputType){
        return TextFormField(
          keyboardType: inputType,
          controller: controller,
          obscureText: obscureText,
          /* style: TextStyle(
            fontSize: 15.0,
          ), */
          decoration: InputDecoration(
           /*  contentPadding:
                EdgeInsets.symmetric(vertical: 5.0, horizontal: 8.0), */
            border: OutlineInputBorder(borderRadius: BorderRadius.circular(5.0)),
            icon: Icon(
              icon,
              color: Colors.black,
              size: 22.0,
            ),
            //hintText: hintText,
            labelText: hintText,
          ),
          validator: (value) {
            if (value.isEmpty) {
              return 'Enter some text';
            }
            return null;
          },
        );
      }
  </code></pre>