When Old Code Fixes Are Actually Bugs

Sometimes the best fix is deleting old fixes.

While consolidating API client code, I found this “normalization” logic in production:

$normalized = str_replace(
    ['SOAP-ENV:', 'xmlns:SOAP-ENV', 'xmlns:ns1'],
    ['soapenv:', 'xmlns:soapenv', 'xmlns'],
    $request
);

It looked intentional. Maybe the API was picky about namespace prefixes? Nope. It was breaking everything.

Removing the normalization fixed server errors that had been happening silently. The API worked fine with standard SOAP envelopes — the str_replace was stripping namespace declarations and causing “undeclared prefix” errors on the server side.

This kind of code survives because: (1) it was probably copy-pasted from a StackOverflow answer, (2) maybe it worked once on a different API, (3) nobody questioned it because it was already there.

When refactoring, actually test the old code path independently. Sometimes those “necessary” workarounds are just ancient bugs in disguise.