[wp-trac] [WordPress Trac] #47454: BC Math isn't used in WordPress core

[WordPress Trac]

#47454: BC Math isn't used in WordPress core
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 Reporter:  bronsonquick                           |       Owner:  (none)
     Type:  defect (bug)                           |      Status:  new
 Priority:  normal                                 |   Milestone:  5.3
Component:  Administration                         |     Version:  5.2
 Severity:  normal                                 |  Resolution:
 Keywords:  has-patch site-health has-screenshots  |     Focuses:
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Comment (by jrf):

 > In this particular case, the example given by @jrf is especially crafted
 to demonstrate a potential problem of PHP doing weird things with
 deliberate type casting (without it, the answer is correct and can be
 further adjusted with round() or floor()).

 Not really. If you use `floor()`, the same would happen and
 congratulations! You've just given someone a $1 discount.
 It's actually not a PHP thing, but to do with how C stores floats in its
 internal memory using binary.


 > It looks like a number of plugins make use of it:

 @TimothyBlynJacobs I'm absolutely appalled that WooCommerce only uses the
 BCMath extension once... this is truly scary and this will lead to
 incorrect calculations.
 Even if it's just one cent discount, for big stores this can add up to big
 $$$.

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Ticket URL: <https://core.trac.wordpress.org/ticket/47454#comment:24>
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