mysqlc: Fix issue by freeing result sets

Change-Id: I8a5f886306e028f06243768376b2a6c55df6063c
Reviewed-on: https://gerrit.libreoffice.org/59210
Tested-by: Jenkins
Reviewed-by: Tamás Bunth <btomi96@gmail.com>
Reviewed-on: https://gerrit.libreoffice.org/59714Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>

connectivity/source/drivers/mysqlc/mysqlc_resultset.cxx

@@ -32,6 +32,8 @@
 #include <cppuhelper/supportsservice.hxx>
 #include <cppuhelper/typeprovider.hxx>
 
+#include <sal/log.hxx>
+
 using namespace rtl;
 #include <comphelper/string.hxx>
 
@@ -559,6 +561,7 @@ void SAL_CALL OResultSet::close()
     checkDisposed(OResultSet_BASE::rBHelper.bDisposed);
 
     mysql_free_result(m_pResult);
+    m_pResult = nullptr;
     dispose();
 }
 

connectivity/source/drivers/mysqlc/mysqlc_statement.cxx

@@ -61,10 +61,10 @@ OCommonStatement::~OCommonStatement() {}
 void OCommonStatement::disposeResultSet()
 {
     // free the cursor if alive
-    if (m_pMysqlResult != nullptr)
+    if (m_xResultSet.is())
     {
-        mysql_free_result(m_pMysqlResult);
-        m_pMysqlResult = nullptr;
+        m_xResultSet.clear();
+        m_pMysqlResult = nullptr; // it is freed by XResultSet
     }
 }