Fix access of tmpStorage in QODBCResult::exec().

Instead of using a list and appending / popping of elements, use
a vector of constant size and access via index to avoid
bookkeeping errors.

Task-number: QTBUG-37831

Change-Id: Icb5a182626c63e693b04daaf7a2f70997d9aeae1
Reviewed-by: Mark Brand <mabrand@mabrand.nl>

1 files changed, 20 insertions, 25 deletions

diff --git a/src/sql/drivers/odbc/qsql_odbc.cpp b/src/sql/drivers/odbc/qsql_odbc.cpp
index ac6d677d54..c950d2c2ef 100644
--- a/src/sql/drivers/odbc/qsql_odbc.cpp
+++ b/src/sql/drivers/odbc/qsql_odbc.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the QtSql module of the Qt Toolkit.
@@ -1323,12 +1323,12 @@ bool QODBCResult::exec()
     if (isSelect())
         SQLCloseCursor(d->hStmt);
 
-    QList<QByteArray> tmpStorage; // holds temporary buffers
-    QVarLengthArray<SQLLEN, 32> indicators(boundValues().count());
+    QVector<QVariant>& values = boundValues();
+    QVector<QByteArray> tmpStorage(values.count(), QByteArray()); // holds temporary buffers
+    QVarLengthArray<SQLLEN, 32> indicators(values.count());
     memset(indicators.data(), 0, indicators.size() * sizeof(SQLLEN));
 
     // bind parameters - only positional binding allowed
-    QVector<QVariant>& values = boundValues();
     int i;
     SQLRETURN r;
     for (i = 0; i < values.count(); ++i) {
@@ -1340,7 +1340,7 @@ bool QODBCResult::exec()
             *ind = SQL_NULL_DATA;
         switch (val.type()) {
             case QVariant::Date: {
-                QByteArray ba;
+                QByteArray &ba = tmpStorage[i];
                 ba.resize(sizeof(DATE_STRUCT));
                 DATE_STRUCT *dt = (DATE_STRUCT *)ba.constData();
                 QDate qdt = val.toDate();
@@ -1357,10 +1357,9 @@ bool QODBCResult::exec()
                                       (void *) dt,
                                       0,
                                       *ind == SQL_NULL_DATA ? ind : NULL);
-                tmpStorage.append(ba);
                 break; }
             case QVariant::Time: {
-                QByteArray ba;
+                QByteArray &ba = tmpStorage[i];
                 ba.resize(sizeof(TIME_STRUCT));
                 TIME_STRUCT *dt = (TIME_STRUCT *)ba.constData();
                 QTime qdt = val.toTime();
@@ -1377,10 +1376,9 @@ bool QODBCResult::exec()
                                       (void *) dt,
                                       0,
                                       *ind == SQL_NULL_DATA ? ind : NULL);
-                tmpStorage.append(ba);
                 break; }
             case QVariant::DateTime: {
-                QByteArray ba;
+                QByteArray &ba = tmpStorage[i];
                 ba.resize(sizeof(TIMESTAMP_STRUCT));
                 TIMESTAMP_STRUCT * dt = (TIMESTAMP_STRUCT *)ba.constData();
                 QDateTime qdt = val.toDateTime();
@@ -1412,7 +1410,6 @@ bool QODBCResult::exec()
                                       (void *) dt,
                                       0,
                                       *ind == SQL_NULL_DATA ? ind : NULL);
-                tmpStorage.append(ba);
                 break; }
             case QVariant::Int:
                 r = SQLBindParameter(d->hStmt,
@@ -1503,6 +1500,7 @@ bool QODBCResult::exec()
                 break;
             case QVariant::String:
                 if (d->unicode) {
+                    QByteArray &ba = tmpStorage[i];
                     QString str = val.toString();
                     if (*ind != SQL_NULL_DATA)
                         *ind = str.length() * sizeof(SQLTCHAR);
@@ -1510,7 +1508,7 @@ bool QODBCResult::exec()
 
                     if (bindValueType(i) & QSql::Out) {
                         const QVarLengthArray<SQLTCHAR> a(toSQLTCHAR(str));
-                        QByteArray ba((const char *)a.constData(), a.size() * sizeof(SQLTCHAR));
+                        ba = QByteArray((const char *)a.constData(), a.size() * sizeof(SQLTCHAR));
                         r = SQLBindParameter(d->hStmt,
                                             i + 1,
                                             qParamType[bindValueType(i) & QSql::InOut],
@@ -1521,10 +1519,9 @@ bool QODBCResult::exec()
                                             (void *)ba.data(),
                                             ba.size(),
                                             ind);
-                        tmpStorage.append(ba);
                         break;
                     }
-                    QByteArray strba((const char *)toSQLTCHAR(str).constData(), str.size()*sizeof(SQLTCHAR));
+                    ba = QByteArray ((const char *)toSQLTCHAR(str).constData(), str.size()*sizeof(SQLTCHAR));
                     r = SQLBindParameter(d->hStmt,
                                           i + 1,
                                           qParamType[bindValueType(i) & QSql::InOut],
@@ -1532,15 +1529,15 @@ bool QODBCResult::exec()
                                           strSize > 254 ? SQL_WLONGVARCHAR : SQL_WVARCHAR,
                                           strSize,
                                           0,
-                                          (SQLPOINTER)strba.constData(),
-                                          strba.size(),
+                                          (SQLPOINTER)ba.constData(),
+                                          ba.size(),
                                           ind);
-                    tmpStorage.append(strba);
                     break;
                 }
                 else
                 {
-                    QByteArray str = val.toString().toUtf8();
+                    QByteArray &str = tmpStorage[i];
+                    str = val.toString().toUtf8();
                     if (*ind != SQL_NULL_DATA)
                         *ind = str.length();
                     int strSize = str.length();
@@ -1555,12 +1552,11 @@ bool QODBCResult::exec()
                                           (void *)str.constData(),
                                           strSize,
                                           ind);
-                    tmpStorage.append(str);
                     break;
                 }
             // fall through
             default: {
-                QByteArray ba = val.toByteArray();
+                QByteArray &ba = tmpStorage[i];
                 if (*ind != SQL_NULL_DATA)
                     *ind = ba.size();
                 r = SQLBindParameter(d->hStmt,
@@ -1573,7 +1569,6 @@ bool QODBCResult::exec()
                                       (void *) ba.constData(),
                                       ba.length() + 1,
                                       ind);
-                tmpStorage.append(ba);
                 break; }
         }
         if (r != SQL_SUCCESS) {
@@ -1617,16 +1612,16 @@ bool QODBCResult::exec()
     for (i = 0; i < values.count(); ++i) {
         switch (values.at(i).type()) {
             case QVariant::Date: {
-                DATE_STRUCT ds = *((DATE_STRUCT *)tmpStorage.takeFirst().constData());
+                DATE_STRUCT ds = *((DATE_STRUCT *)tmpStorage.at(i).constData());
                 values[i] = QVariant(QDate(ds.year, ds.month, ds.day));
                 break; }
             case QVariant::Time: {
-                TIME_STRUCT dt = *((TIME_STRUCT *)tmpStorage.takeFirst().constData());
+                TIME_STRUCT dt = *((TIME_STRUCT *)tmpStorage.at(i).constData());
                 values[i] = QVariant(QTime(dt.hour, dt.minute, dt.second));
                 break; }
             case QVariant::DateTime: {
                 TIMESTAMP_STRUCT dt = *((TIMESTAMP_STRUCT*)
-                                        tmpStorage.takeFirst().constData());
+                                        tmpStorage.at(i).constData());
                 values[i] = QVariant(QDateTime(QDate(dt.year, dt.month, dt.day),
                                QTime(dt.hour, dt.minute, dt.second, dt.fraction / 1000000)));
                 break; }
@@ -1642,7 +1637,7 @@ bool QODBCResult::exec()
             case QVariant::String:
                 if (d->unicode) {
                     if (bindValueType(i) & QSql::Out) {
-                        QByteArray first = tmpStorage.takeFirst();
+                        const QByteArray &first = tmpStorage.at(i);
                         QVarLengthArray<SQLTCHAR> array;
                         array.append((SQLTCHAR *)first.constData(), first.size());
                         values[i] = fromSQLTCHAR(array, first.size()/sizeof(SQLTCHAR));
@@ -1652,7 +1647,7 @@ bool QODBCResult::exec()
                 // fall through
             default: {
                 if (bindValueType(i) & QSql::Out)
-                    values[i] = tmpStorage.takeFirst();
+                    values[i] = tmpStorage.at(i);
                 break; }
         }
         if (indicators[i] == SQL_NULL_DATA)