Non-locale aware of scale and translate

[JercSi]

When using a Slovenian locale, output of scale and translate is wrong.

Expected result: scale(3.123)
Actual result: scale(3,123) which means wrong scale
Issue: Slovenian decimal separator is ',' and not a '.' (https://www.localeplanet.com/icu/sl-SI/index.html)

Solution: when using a sprintf use a non-local aware float formatting.

Test code

$precision = 3;
$size = 3.1234;

$xml = new \XMLWriter();
$xml->openMemory();
$xml->startDocument('1.0', 'UTF-8');
$xml->startElement('svg');
$xml->writeAttribute('xmlns', 'http://www.w3.org/2000/svg');
$xml->writeAttribute('version', '1.1');
$xml->writeAttribute('width', (string) $size);
$xml->writeAttribute('height', (string) $size);
$xml->writeAttribute('viewBox', '0 0 '. $size . ' ' . $size);

// ========= Current code
// English: 3.1234
// Result is scale for x and y the same = 3.1234
setlocale(LC_ALL, array('English', 'en', 'en_GB.UTF-8'));
$xml->startElement('g');
$xml->writeAttribute(
    'transform',
    sprintf('scale(%s)', round($size, $precision))
);
$xml->text("English");
$xml->endElement();

// Slovenian: 3,1234
// Result is scale in x=3 and y=1234
setlocale(LC_ALL,array('sl_SI.UTF-8', 'Slovenian', 'sl_SI'));
$xml->startElement('g');
$xml->writeAttribute(
    'transform',
    sprintf('scale(%s)', round($size, $precision))
);
$xml->text("Slovenian with a bug");
$xml->endElement();

// ========= With fixed code
// Using a 'F': The argument is treated as a float and presented as a floating-point number (non-locale aware)
setlocale(LC_ALL, array('English', 'en', 'en_GB.UTF-8'));
$xml->startElement('g');
$xml->writeAttribute(
    'transform',
    sprintf('scale(%.' . $precision . 'F)', round($size, $precision))
);
$xml->text("English");
$xml->endElement();
setlocale(LC_ALL,array('sl_SI.UTF-8', 'Slovenian', 'sl_SI'));
$xml->startElement('g');
$xml->writeAttribute(
    'transform',
    sprintf('scale(%.' . $precision . 'F)', round($size, $precision))
);
$xml->text("Slovenian fixed");
$xml->endElement();

$xml->endDocument();
echo $xml->outputMemory();

Test code result

<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="3.1234" height="3.1234" viewBox="0 0 3.1234 3.1234">
    <g transform="scale(3.123)">English</g>
    <g transform="scale(3,123)">Slovenian with a bug</g>
    <g transform="scale(3.123)">English</g>
    <g transform="scale(3.123)">Slovenian fixed</g>
</svg>

[codecov-commenter]

Codecov Report

Merging #100 (84cc0d5) into master (0069435) will decrease coverage by 0.32%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master     #100      +/-   ##
============================================
- Coverage     63.43%   63.11%   -0.33%     
+ Complexity      934      928       -6     
============================================
  Files            47       47              
  Lines          3036     2879     -157     
============================================
- Hits           1926     1817     -109     
+ Misses         1110     1062      -48     

Impacted Files	Coverage Δ
src/Renderer/Image/SvgImageBackEnd.php	0.00% <0.00%> (ø)
src/Renderer/Color/Gray.php	41.66% <0.00%> (-4.49%)	⬇️
src/Renderer/Image/ImagickImageBackEnd.php	62.34% <0.00%> (-2.19%)	⬇️
src/Renderer/Color/Rgb.php	43.33% <0.00%> (-1.83%)	⬇️
src/Writer.php	90.00% <0.00%> (-1.67%)	⬇️
src/Common/BitMatrix.php	35.77% <0.00%> (-1.62%)	⬇️
src/Common/ErrorCorrectionLevel.php	78.57% <0.00%> (-1.43%)	⬇️
src/Common/CharacterSetEci.php	51.42% <0.00%> (-1.35%)	⬇️
src/Renderer/RendererStyle/RendererStyle.php	66.66% <0.00%> (-1.34%)	⬇️
src/Encoder/QrCode.php	63.33% <0.00%> (-1.19%)	⬇️
... and 38 more

---

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[vlakoff]

As I mentioned in this comment, the changes introduced by this PR are no longer necessary since PHP 8.0. They should be reverted to avoid the redundant trailing zeroes.

edit: submitted #218 to address this.