The tests stay; they just no longer run in separate processes. I think that only 2 tests still require separate processes - Helper/SampleTest and Tcpdf/NoDieTest. Aside from a new internal method in IOFactory, all the changes here are to test members.
We do not recommend it, but users can call the Php function `setlocale` and that might affect the character used as currency symbol. A problem arises when the caller to setlocale does not specify a character set - in that case, Php will attempt to return its `localeconv()` values in a single-byte character set rather than UTF-8. This is particularly problematic for currency symbols. PhpSpreadsheet till now has accepted such a character, and that can lead to corrupt spreadsheets. It is changed to validate the currency symbol as UTF-8, and fall back to a different choice if not (e.g. EUR rather than 0x80, which is how the euro symbol is depicted in Win-1252).
An additional problem arises because Linux systems seem to return the alternate symbol with a trailing blank, but Windows systems do not. To allow callers to get a consistent result, a parameter is added to `getCurrencyCode` which will trim or not (default) the currency code.
oleibman