Fix: lv_LV generating invalid personal identity numbers

[edgarsn]

What is the reason for this PR?

Generated latvian personal identity number (PIN) part after dash is invalid. By implementing this, developers will have ability to work with randomly generated, valid PIN, especially if somewhere in tests they rely on a valid PIN.

• A new feature
• Fixed an issue (No issue linked)

Author's checklist

• Follow the Contribution Guide
• New features and changes are documented

Summary of changes

https://en.wikipedia.org/wiki/National_identification_number#Latvia

Shortly:

• First digit after dash is century the person is born in (19c. = 0, 20c. = 1, 21c. = 2). This was random number.
• Next 3 digits are serial number in given date. Range: 000 - 999. May stay random.
• Last digit is checksum of all previous digits. This was calculated wrong by using Luhn.

In this PR all theese things are taken into account, making PIN totally valid.

About checksum digit formula

Format: ABCDEF-XGHIZ
Formula: (1101-(1*A+6*B+3*C+7*D+9*E+10*F+5*X+8*G+4*H+2*I)) | Mod 11 | Mod 10

Example:
Birth date: 1981-05-24
Century: 1
Serial number (random): 579
PIN without checksum (X) yet: 240581-1579X

Inserting real numbers into formula:

(1101 - (1 * 2 + 6 * 4 + 3 * 0 + 7 * 5 + 9 * 8 + 10 * 1 + 5 * 1 + 8 * 5 + 4 * 7 + 2 * 9)) | Mod 11 | Mod 10 = 9

Which makes PIN to be: 240581-15799

Review checklist

• All checks have passed
• Changes are approved by maintainer

[edgarsn]

About failing psalm check - I don't have a experience using psalm, but seems that changing foreach loop to this fixes the check.

foreach ($partialNumberSplit as $key => $digit) {
  if (!isset($idDigitValidator[$key])) {
	continue;
  }
  
  $total += $idDigitValidator[$key] * (int) $digit;
}

... but is that the best way how to deal with it?

[pimjansen]

About failing psalm check - I don't have a experience using psalm, but seems that changing foreach loop to this fixes the check.

foreach ($partialNumberSplit as $key => $digit) {

  if (!isset($idDigitValidator[$key])) {

	continue;

  }

  

  $total += $idDigitValidator[$key] * (int) $digit;

}

... but is that the best way how to deal with it?

Skip the continue and make the if the other way around only execute if exists. Originally its a possible nullpointer exception so