Update EAN13.swift

[hrabkin]

EAN13 calculation corrected - was failing on this one "5903779001320"

The digits in even positions are: 9, 3, 7, 0, 1, 2, their sum is 22, multiplied by 3 it is 66;
The digits in odd positions (except the last one) are: 5, 0, 7, 9, 0, 3, their sum is 24, added to the number above it is 90;
Dividing 90 by 10 gives us 0 as a remainder;
It is zero, so just using it as is.

[nrivard]

This seems inherently unsafe if after the compactMap there are zero elements in digits. Previous code was written a long time ago I should have probably made it safer long ago 😂 Haven't looked at this code in awhile so maybe there are other verification steps that make sure it's the proper number of digits but you may want to check that value.count == digits.count

[hrabkin]

@nrivard yes, I've seen it, but on line 16 you checked digits, so it is actually fine:

BarcodeView/Sources/BarcodeView/Models/EAN13.swift

Line 16 in 1c18b32

guard !verifyChecksum || EAN13.verifyChecksumDigit(value: value), let digits = EAN13.digits(value: value) else { return nil }

[nrivard]

Also @hrabkin thank you for contributing 😄