SWMM output API bug

[cbuahin]

Function for retrieving system variable assigns an address to a local variable to the output pointer. This causes an error when the local variable goes out of scope and is generally inconsistent with the strategy used else where in the code.

int EXPORT_OUT_API SMO_getSystemAttribute(SMO_Handle p_handle, int periodIndex,
    SMO_systemAttribute attr, float **outValueArray, int *length)
//
//  Purpose: For the system at given time, get a particular attribute.
//
{
    int     errorcode = 0;
    float   temp;
    data_t *p_data;

    p_data = (data_t *)p_handle;

    if (p_data == NULL)
        errorcode = -1;
    else if (periodIndex < 0 || periodIndex >= p_data->Nperiods)
        errorcode = 422;
    else {
        // don't need to loop since there's only one system
        temp = getSystemValue(p_data, periodIndex, attr);

        *outValueArray = &temp;
        *length        = 1;
    }

https://github.com/USEPA/Stormwater-Management-Model/blob/develop/src/outfile/swmm_output.c#L783-L796