Sometimes, we may need to replace some special characters with white space. There is no option to add white space in the "replacements" settings. If we try to add white space then the code will trim the white space.
validateConfigurationForm() in RegexReplace.php
$replacements = [];
$value = rtrim(preg_replace('/\r\n|\r|\n/', "\n", $form_state->getValue('replacements')), "\n");
if (!empty($value)) {
foreach (explode("\n", $value) as $replacement) {
$replacements[] = trim($replacement);
}
}Don't use trim if the string only contains a single white space
$replacements[] = ($replacement != " ") ? trim($replacement) : $replacement;
Active
4.3
Code
The happens for newlines.
A quick workaround could be to enter HTML entities instead that get converted by the HtmlFilter processor later.
As a patch we could add a hint to the description of the Replacements text field.