This is a dereference of null pointer problem - in both the ANSI C & gSoap domains:
I am using the following public WSDL:
http://www.mobilefish.com/services/web_service/countries.php?wsdl
and have tested its behavior using soapUI.
I created client-side only ANSI C bindings using the wsdl2h and soapcpp2 utilities.
The problem:
In previous gsoap projects, results structures in the client soap_call functions (the fifth argument) required no initialization other than something like:
struct ns2__countryInfoByIanaResponse out, *pOut
pOut= &out;
this has always been sufficient until this project.
The client soap_call looks like this:
soap_call_ns2__countryInfoByIana(&soap, NULL, NULL, pIn, pOut); /* SOAP 1.2 RPC return element...*/
pIn for this project is defined as a char *, populated with a two character IANA code such as "us", or "nz". The return structure pOut for this particular call is shaped like this:
struct ns2__countryInfoByIanaResponse
{
struct ns1__CountryData *countryinfo;
}
With ns1__CountryData shaped like this:
struct ns1__CountryData
{
char *ianacode; /* required element of type xsd:string */
char *countryname; /* required element of type xsd:string */
float latitude; /* required element of type xsd:float */
float longitude; /* required element of type xsd:float */
};
A call to this function from my application is therefore set up like this:
//declare response structure:
struct ns2__countryInfoByIanaResponse o, *pO;
void main(void)
{
pO = &o;
if(GetCountryInfo(buf, pO)==0)
{
pO->countryinfo->countryname; //Error Occurs Here...
}
}
The error occurs at pO->countryinfo as a dereference of null pointer
GetCountryInfo is defined here:
int DLL_EXPORT GetCountryInfo(char *pIn, struct ns2__countryInfoByIanaResponse *pOut)
{
int status = 0;
size_t len=2048;
char buf[2048];
if (soap_call_ns2__countryInfoByIana(&soap, NULL, NULL, pIn, pOut)== SOAP_OK)
{
status = 0;
}
else
{
//soap_print_fault(&soap, stderr);
soap_sprint_fault(&soap, buf, len);
MessagePopup("soap error", buf);
status = 1;
}
return status;
}
Other gSoap projects using similar output structure shapes (i.e. structures containing structures containing char *) returned fully populated results when initialized with nothing other than what I have shown above.
Any ideas? Please let me know if I can provide any further details. Thanks.