SQLite provider m_nTotalProps is not initialized when select aggregates

[christinebao]

Reported from Autodesk QA.

1. In mapguide, load attached sqlite Hawaii_N83_4.sqlite.
2. In mapagent, execute Feature->SelectAggregates, Class nam = lulc_n83, Computed Properties = CeilPerim;Ceil(PERIMETER).
3. Report error:

An exception occurred in FDO component. Property index '0' is out of bounds. (Cause: , Root Cause: Property index '0' is out of bounds.)

[christinebao]

The sqlite file is 9M, too large to attach.

[christinebao]

This exception happen in

void SltReader::ValidateIndex(sqlite3_stmt *pStmt, int index)
{    
    if (index < 0 || index >= m_nTotalProps)
    {
		wchar_t tmp[15];
		swprintf(tmp, 15, L"%d", index);
        throw FdoCommandException::Create((std::wstring(L"Property index \'") + tmp + L"\' is out of bounds.").c_str());
    }

m_nTotalProps is a memory cache to indicate how many columns the table has. It is initialized in each constructor, but forget to initialize in one constructor SltReader::SltReader(SltConnection* connection, FdoIdentifierCollection* props, FdoParameterValueCollection* parmValues, const char* fcname, const char* sql) in case props->GetCount() is 0.

[christinebao]

Submit to trunk at r7217, and Autodesk 4.0 branch at r7218.