$_FILES['imagem'] is undefined in Firefox - codeigniter

Question

My website is built using Codeigniter, and there's an area for users to modify their information. This area allows users to choose a profile picture, and when editing it, the selected picture is previewed. In case they don't choose a new one, there's a hidden field storing its name, which is passed to the controller to specify the same image name, but if the user decides to change it, the new name is passed to the controller.
public function edit($id)
{
$this->input->post('tipo_usuario') === 'F' ? $validator = 'editar_pessoa_fisica' : $validator = 'editar_pessoa_juridica';
if ($this->form_validation->run($validator)) {
$data = array();
$data['nome_razao_social'] = $this->input->post('nome_razao_social');
$data['nome_responsavel'] = $this->input->post('nome_responsavel');
$data['nome_fantasia'] = $this->input->post('nome_fantasia');
$data['cpf_cnpj'] = $this->input->post('cpf_cnpj');
$data['telefone'] = $this->input->post('telefone');
$data['telefone_2'] = $this->input->post('telefone_2');
$data['email'] = $this->input->post('email');
$data['novo_email'] = $this->input->post('novo_email');
$data['senha'] = md5($this->input->post('senha'));
$data['cep'] = $this->input->post('cep');
$data['logradouro'] = $this->input->post('logradouro');
$data['id_cidade'] = $this->input->post('id_cidade');
$data['id_estado'] = $this->input->post('id_estado');
$data['numero'] = $this->input->post('numero');
$data['complemento'] = $this->input->post('complemento');
$data['tipo_usuario'] = $this->input->post('tipo_usuario');
/*
HERE IS IN CASE THE USER DOES NOT CHANGE HIS PROFILE PICTURE
*/
$data['imagem'] = $this->input->post('imagem_old');
$data['url'] = $this->input->post('url');
// Nova senha?
if ($this->input->post('novasenha') !== '') {
$data['senha'] = md5($this->input->post('novasenha'));
} else {
$data['senha'] = $this->input->post('senha');
}
/*
HERE IS IN CASE THE USER CHANGES HIS PROFILE PICTURE
*/
// Nova imagem?
if ($_FILES['imagem']['name'] !== '') {
$data['imagem'] = $_FILES['imagem']['name'];
}
// Novo e-mail?
if ($this->input->post('email') !== $this->input->post('novoemail')) {
$data['novo_email'] = $this->input->post('novoemail');
$this->Usuarios_model->update($data, $id);
$this->Usuarios_model->send_confirmation_email($data['novo_email'], $data['email']);
}
if ($this->input->post('novo_novo_email') !== $this->input->post('novo_email')) {
$data['novo_email'] = $this->input->post('novo_novo_email');
$this->Usuarios_model->update($data, $id);
$this->Usuarios_model->send_confirmation_email($data['novo_email'], $data['email']);
}
if ($this->Usuarios_model->update($data, $id)) {
$this->upload->do_upload('imagem');
$this->session->set_flashdata('message', 'Dados alterados');
echo json_encode(array(
'redirect' => '/usuario/painel'
));
}
} else {
echo json_encode(array(
'type' => 'validation',
'message' => validation_errors(),
));
}
}
This is the HTML:
<form action="/auto/usuario/edit/<?php echo $id_usuario; ?>" method="POST" class="formulario" enctype="multipart/form-data">
<input type="hidden" name="tipo_usuario" value="F"/>
<div class="p100">
<span class="titulo">Foto de Perfil</span>
<div class="imagem_destaque img_perfil image-trigger">
<div class="file-upload-trigger">
<input type="file" name="imagem" class="none file-chooser"/>
<img src="/uploads/perfil/<?php echo $u['imagem'] ?>" class="preview more"/>
</div>
</div>
<input type="hidden" name="imagem_old" value="<?php echo $u['imagem']; ?>"/>
</div>
With Google Chrome, it works fine, but in Firefox 45, if I do not choose a new image, an error is thrown:
Severity: Notice
Message: Undefined index: imagem
Filename: controllers/Usuario.php
Line Number: 362
It only works locally.

Answer 1

If you do not upload a new image, your $_FILES[] is undefined, as the error says. To check if the user has changed his image you should do:
if ( isset($_FILES['imagem']['name']) ) {
$data['imagem'] = $_FILES['imagem']['name'];
}