Warrants are not issued by the company you buy shares in, they are issued by financial institutions like banks. When a warrant is issued the financial institution is actually holding the same number of underlying shares, so when an investor pays the second instalment and takes hold of the shares there are no new shares issued by the trading company. You actually acquire the underlying shares from the financial institution.
Other countries may be different, but for warrants traded in Australia refer to the following document Understanding WarrantsUnderstanding Warrants.