Bug: can't update currency rate

[dolibarr95]

Bug

Can't update the rate of a currency

Environment

• Version: 5.0.0
• OS: Linux otos.planethoster.net
• Web server: LiteSpeed
• PHP: 5.6.28
• Database: MySQL or MariaDB 10.1.19-MariaDB
• URL(s): admin/multicurrency.php

Expected and actual behavior

I think the bug come from the variable $rate called with the GETPOST function. Because when i read it in core/lib/functions.lib.php there is no 'float' case.

elseif ($action == 'update_currency')
{
	$submit = GETPOST('submit', 'alpha');
	
	if ($submit == $langs->trans('Modify'))
	{
		$fk_multicurrency = GETPOST('fk_multicurrency', 'int');
		$rate = GETPOST('rate', 'float');
		$currency = new MultiCurrency($db);
		
		if ($currency->fetch($fk_multicurrency) > 0)
		{
			$currency->updateRate($rate);
		}	
	}
	elseif ($submit == $langs->trans('Delete'))
	{
		$fk_multicurrency = GETPOST('fk_multicurrency', 'int');
		$currency = new MultiCurrency($db);
		
		if ($currency->fetch($fk_multicurrency) > 0)
		{
			if ($currency->delete() > 0) setEventMessages($langs->trans('RecordDeleted'), array());
			else setEventMessages($langs->trans('ErrorDeleteCurrencyFail'), array(), 'errors');
		}
	}
}

Steps to reproduce the behavior

Dolibarr runs with EUR
Activate the multicurrency module
Create a new currency USD
Update the USD rate

tks for reading!