QPSQLResultPrivate: do not duplicate reference to private driver

The "private driver" is already known, so don't keep an extra reference
to it.

Change-Id: I34ec4108694bfbc3da3107f79598ae50a699911c
Reviewed-by: Israel Lins Albuquerque <israelins85@yahoo.com.br>
Reviewed-by: Mark Brand <mabrand@mabrand.nl>

src/sql/drivers/psql/qsql_psql.cpp

@@ -194,12 +194,12 @@ PGresult * QPSQLDriverPrivate::exec(const QString & stmt) const
 class QPSQLResultPrivate
 {
 public:
-    QPSQLResultPrivate(QPSQLResult *qq): q(qq), privDriver(0), result(0), currentSize(-1), preparedQueriesEnabled(false) {}
+    QPSQLResultPrivate(QPSQLResult *qq): q(qq), result(0), currentSize(-1), preparedQueriesEnabled(false) {}
     static QString fieldSerial(int i) { return QLatin1Char('$') + QString::number(i + 1); }
     void deallocatePreparedStmt();
+    const QPSQLDriverPrivate * privDriver() const { return reinterpret_cast<const QPSQLDriver *>(q->driver())->d; }
 
     QPSQLResult *q;
-    const QPSQLDriverPrivate *privDriver;
     PGresult *result;
     int currentSize;
     bool preparedQueriesEnabled;
@@ -238,7 +238,7 @@ bool QPSQLResultPrivate::processResults()
         return true;
     }
     q->setLastError(qMakeError(QCoreApplication::translate("QPSQLResult",
-                    "Unable to create query"), QSqlError::StatementError, privDriver, result));
+                    "Unable to create query"), QSqlError::StatementError, privDriver(), result));
     return false;
 }
 
@@ -291,19 +291,18 @@ static QVariant::Type qDecodePSQLType(int t)
 void QPSQLResultPrivate::deallocatePreparedStmt()
 {
     const QString stmt = QLatin1String("DEALLOCATE ") + preparedStmtId;
-    PGresult *result = privDriver->exec(stmt);
+    PGresult *result = privDriver()->exec(stmt);
 
     if (PQresultStatus(result) != PGRES_COMMAND_OK)
-        qWarning("Unable to free statement: %s", PQerrorMessage(privDriver->connection));
+        qWarning("Unable to free statement: %s", PQerrorMessage(privDriver()->connection));
     PQclear(result);
     preparedStmtId.clear();
 }
 
-QPSQLResult::QPSQLResult(const QPSQLDriver* db, const QPSQLDriverPrivate* p)
+QPSQLResult::QPSQLResult(const QPSQLDriver* db)
     : QSqlResult(db)
 {
     d = new QPSQLResultPrivate(this);
-    d->privDriver = p;
     d->preparedQueriesEnabled = db->hasFeature(QSqlDriver::PreparedQueries);
 }
 
@@ -371,7 +370,7 @@ QVariant QPSQLResult::data(int i)
     case QVariant::Bool:
         return QVariant((bool)(val[0] == 't'));
     case QVariant::String:
-        return d->privDriver->isUtf8 ? QString::fromUtf8(val) : QString::fromLatin1(val);
+        return d->privDriver()->isUtf8 ? QString::fromUtf8(val) : QString::fromLatin1(val);
     case QVariant::LongLong:
         if (val[0] == '-')
             return QString::fromLatin1(val).toLongLong();
@@ -469,7 +468,7 @@ bool QPSQLResult::reset (const QString& query)
         return false;
     if (!driver()->isOpen() || driver()->isOpenError())
         return false;
-    d->result = d->privDriver->exec(query);
+    d->result = d->privDriver()->exec(query);
     return d->processResults();
 }
 
@@ -485,7 +484,7 @@ int QPSQLResult::numRowsAffected()
 
 QVariant QPSQLResult::lastInsertId() const
 {
-    if (d->privDriver->pro >= QPSQLDriver::Version81) {
+    if (d->privDriver()->pro >= QPSQLDriver::Version81) {
         QSqlQuery qry(driver()->createResult());
         // Most recent sequence value obtained from nextval
         if (qry.exec(QLatin1String("SELECT lastval();")) && qry.next())
@@ -507,7 +506,7 @@ QSqlRecord QPSQLResult::record() const
     int count = PQnfields(d->result);
     for (int i = 0; i < count; ++i) {
         QSqlField f;
-        if (d->privDriver->isUtf8)
+        if (d->privDriver()->isUtf8)
             f.setName(QString::fromUtf8(PQfname(d->result, i)));
         else
             f.setName(QString::fromLocal8Bit(PQfname(d->result, i)));
@@ -579,11 +578,11 @@ bool QPSQLResult::prepare(const QString &query)
     const QString stmtId = qMakePreparedStmtId();
     const QString stmt = QString::fromLatin1("PREPARE %1 AS ").arg(stmtId).append(QSqlResultPrivate::positionalToNamedBinding(query, QPSQLResultPrivate::fieldSerial));
 
-    PGresult *result = d->privDriver->exec(stmt);
+    PGresult *result = d->privDriver()->exec(stmt);
 
     if (PQresultStatus(result) != PGRES_COMMAND_OK) {
         setLastError(qMakeError(QCoreApplication::translate("QPSQLResult",
-                                "Unable to prepare statement"), QSqlError::StatementError, d->privDriver, result));
+                                "Unable to prepare statement"), QSqlError::StatementError, d->privDriver(), result));
         PQclear(result);
         d->preparedStmtId.clear();
         return false;
@@ -608,7 +607,7 @@ bool QPSQLResult::exec()
     else
         stmt = QString::fromLatin1("EXECUTE %1 (%2)").arg(d->preparedStmtId).arg(params);
 
-    d->result = d->privDriver->exec(stmt);
+    d->result = d->privDriver()->exec(stmt);
 
     return d->processResults();
 }
@@ -892,7 +891,7 @@ void QPSQLDriver::close()
 
 QSqlResult *QPSQLDriver::createResult() const
 {
-    return new QPSQLResult(this, d);
+    return new QPSQLResult(this);
 }
 
 bool QPSQLDriver::beginTransaction()

src/sql/drivers/psql/qsql_psql_p.h

@@ -68,7 +68,6 @@ typedef struct pg_result PGresult;
 QT_BEGIN_NAMESPACE
 
 class QPSQLResultPrivate;
-class QPSQLDriverPrivate;
 class QPSQLDriver;
 class QSqlRecordInfo;
 
@@ -76,7 +75,7 @@ class QPSQLResult : public QSqlResult
 {
     friend class QPSQLResultPrivate;
 public:
-    QPSQLResult(const QPSQLDriver* db, const QPSQLDriverPrivate* p);
+    QPSQLResult(const QPSQLDriver* db);
     ~QPSQLResult();
 
     QVariant handle() const;
@@ -101,8 +100,12 @@ private:
     QPSQLResultPrivate *d;
 };
 
+class QPSQLDriverPrivate;
+
 class Q_EXPORT_SQLDRIVER_PSQL QPSQLDriver : public QSqlDriver
 {
+    friend class QPSQLResultPrivate;
+
     Q_OBJECT
 public:
     enum Protocol {