ext/soap: Windows handles query strings differently

If I'm right, that would also happen on other OSs if ext/soap is built as shared library.

Nope, has nothing to do with shared libs – Windows specific issue.

The problem is that SoapServer expects "wsdl" as query string to deliver the WSDL. However, if a query string doesn't contain an equals sign, command line options are ignored on Windows. So either hack-around by making SoapServer more deliberate:

 ext/soap/soap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ext/soap/soap.c b/ext/soap/soap.c
index 48a7fc8885..d7dfc4ecd5 100644
--- a/ext/soap/soap.c
+++ b/ext/soap/soap.c
@@ -1297,7 +1297,8 @@ PHP_METHOD(SoapServer, handle)
 	if (SG(request_info).request_method &&
 	    strcmp(SG(request_info).request_method, "GET") == 0 &&
 	    SG(request_info).query_string &&
-	    stricmp(SG(request_info).query_string, "wsdl") == 0) {
+	    (stricmp(SG(request_info).query_string, "wsdl") == 0 ||
+	     stricmp(SG(request_info).query_string, "wsdl=") == 0)) {
 
 		if (service->sdl) {
 /*

or apply a proper fix for the tests, namely to spawn a php-cgi process with the command line options, and then send a CGI request and verify the response. Certainly possible, but I'm not sure it's worth the effort.

Originally posted by @cmb69 in https://github.com/php/php-src/issues/17432#issuecomment-2589593847

Start in ext/soap/soap.c at SoapServer::handle and review how the Windows CGI query string behavior affects the "wsdl" request. Compare the proposed one-file handling change with the alternative CGI test approach described in the issue. Done means Windows serves the WSDL for the affected query string and the behavior is covered by appropriate regression testing.