Fixes failed queries when mysql auto-prepares

Queries like "Show Index" etc, fail on mysql when automatically prepared
due to a bug in several versions of mysql. Basically anything but a
select query will fail. This fixes this by making the user explicitly
prepare the query if they want to, and the blame then falls on them
if they try and prepare a statement likely to fail.  This fix also
seems to result in a speedup for single-execution queries, possibly
due to reduction in roundtrip communications.

All autotests pass & behaviour conforms to documentation.

Task-number: 252450, 246125

1 files changed, 21 insertions, 26 deletions

diff --git a/src/sql/drivers/mysql/qsql_mysql.cpp b/src/sql/drivers/mysql/qsql_mysql.cpp
index bd6f7b9..39ef1ef 100644
--- a/src/sql/drivers/mysql/qsql_mysql.cpp
+++ b/src/sql/drivers/mysql/qsql_mysql.cpp
@@ -85,11 +85,10 @@ public:
 #else
         tc(0),
 #endif
-        preparedQuerys(false), preparedQuerysEnabled(false) {}
+        preparedQuerysEnabled(false) {}
     MYSQL *mysql;
     QTextCodec *tc;
 
-    bool preparedQuerys;
     bool preparedQuerysEnabled;
 };
 
@@ -172,6 +171,7 @@ public:
 #if MYSQL_VERSION_ID >= 40108
         , stmt(0), meta(0), inBinds(0), outBinds(0)
 #endif
+        , preparedQuery(false)
         {
             connect(dp, SIGNAL(destroyed()), this, SLOT(driverDestroyed()));
         }
@@ -209,6 +209,9 @@ public:
     MYSQL_BIND *inBinds;
     MYSQL_BIND *outBinds;
 #endif
+
+    bool preparedQuery;
+
 private Q_SLOTS:
     void driverDestroyed() { driver = NULL; }
 };
@@ -399,7 +402,7 @@ QMYSQLResult::~QMYSQLResult()
 QVariant QMYSQLResult::handle() const
 {
 #if MYSQL_VERSION_ID >= 40108
-    if(d->driver && d->driver->d->preparedQuerys)
+    if(d->preparedQuery)
         return d->meta ? qVariantFromValue(d->meta) : qVariantFromValue(d->stmt);
     else
 #endif
@@ -454,9 +457,6 @@ void QMYSQLResult::cleanup()
     d->row = NULL;
     setAt(-1);
     setActive(false);
-
-    if(d->driver)
-        d->driver->d->preparedQuerys = d->driver->d->preparedQuerysEnabled;
 }
 
 bool QMYSQLResult::fetch(int i)
@@ -474,7 +474,7 @@ bool QMYSQLResult::fetch(int i)
     }
     if (at() == i)
         return true;
-    if (d->driver->d->preparedQuerys) {
+    if (d->preparedQuery) {
 #if MYSQL_VERSION_ID >= 40108
         mysql_stmt_data_seek(d->stmt, i);
 
@@ -507,7 +507,7 @@ bool QMYSQLResult::fetchNext()
 {
     if(!d->driver)
         return false;
-    if (d->driver->d->preparedQuerys) {
+    if (d->preparedQuery) {
 #if MYSQL_VERSION_ID >= 40108
         if (mysql_stmt_fetch(d->stmt))
             return false;
@@ -534,7 +534,7 @@ bool QMYSQLResult::fetchLast()
     }
 
     my_ulonglong numRows;
-    if (d->driver->d->preparedQuerys) {
+    if (d->preparedQuery) {
 #if MYSQL_VERSION_ID >= 40108
         numRows = mysql_stmt_num_rows(d->stmt);
 #else
@@ -574,7 +574,7 @@ QVariant QMYSQLResult::data(int field)
     int fieldLength = 0;
     const QMYSQLResultPrivate::QMyField &f = d->fields.at(field);
     QString val;
-    if (d->driver->d->preparedQuerys) {
+    if (d->preparedQuery) {
         if (f.nullIndicator)
             return QVariant(f.type);
 
@@ -634,7 +634,7 @@ QVariant QMYSQLResult::data(int field)
     case QVariant::ByteArray: {
 
         QByteArray ba;
-        if (d->driver->d->preparedQuerys) {
+        if (d->preparedQuery) {
             ba = QByteArray(f.outField, f.bufLength);
         } else {
             ba = QByteArray(d->row[field], fieldLength);
@@ -651,7 +651,7 @@ QVariant QMYSQLResult::data(int field)
 
 bool QMYSQLResult::isNull(int field)
 {
-   if (d->driver->d->preparedQuerys)
+   if (d->preparedQuery)
        return d->fields.at(field).nullIndicator;
    else
        return d->row[field] == NULL;
@@ -662,11 +662,9 @@ bool QMYSQLResult::reset (const QString& query)
     if (!driver() || !driver()->isOpen() || driver()->isOpenError() || !d->driver)
         return false;
 
-    if(d->driver->d->preparedQuerysEnabled && prepare(query)) {
-        d->driver->d->preparedQuerys = true;
-        return exec();
-    }
-    d->driver->d->preparedQuerys = false;
+    d->preparedQuery = false;
+
+    cleanup();
 
     const QByteArray encQuery(fromUnicode(d->driver->d->tc, query));
     if (mysql_real_query(d->driver->d->mysql, encQuery.data(), encQuery.length())) {
@@ -699,7 +697,7 @@ bool QMYSQLResult::reset (const QString& query)
 int QMYSQLResult::size()
 {
     if (d->driver && isSelect())
-        if (d->driver->d->preparedQuerys)
+        if (d->preparedQuery)
 #if MYSQL_VERSION_ID >= 40108
             return mysql_stmt_num_rows(d->stmt);
 #else
@@ -721,7 +719,7 @@ QVariant QMYSQLResult::lastInsertId() const
     if (!isActive() || !d->driver)
         return QVariant();
 
-    if (d->driver->d->preparedQuerys) {
+    if (d->preparedQuery) {
 #if MYSQL_VERSION_ID >= 40108
         quint64 id = mysql_stmt_insert_id(d->stmt);
         if (id)
@@ -743,7 +741,7 @@ QSqlRecord QMYSQLResult::record() const
         return info;
 
 #if MYSQL_VERSION_ID >= 40108
-    res = d->driver->d->preparedQuerys ? d->meta : d->result;
+    res = d->preparedQuery ? d->meta : d->result;
 #else
     res = d->result;
 #endif
@@ -856,7 +854,7 @@ bool QMYSQLResult::prepare(const QString& query)
         return false;
 #if MYSQL_VERSION_ID >= 40108
     cleanup();
-    if (!d->driver->d->preparedQuerys)
+    if (!d->driver->d->preparedQuerysEnabled)
         return QSqlResult::prepare(query);
 
     int r;
@@ -886,6 +884,7 @@ bool QMYSQLResult::prepare(const QString& query)
     }
 
     setSelect(d->bindInValues());
+    d->preparedQuery = true;
     return true;
 #else
     return false;
@@ -896,7 +895,7 @@ bool QMYSQLResult::exec()
 {
     if (!d->driver)
         return false;
-    if (!d->driver->d->preparedQuerys)
+    if (!d->preparedQuery)
         return QSqlResult::exec();
     if (!d->stmt)
         return false;
@@ -1338,9 +1337,6 @@ QSqlIndex QMYSQLDriver::primaryIndex(const QString& tablename) const
     if (!isOpen())
         return idx;
 
-    prepQ = d->preparedQuerysEnabled;
-    d->preparedQuerysEnabled = false;
-
     QSqlQuery i(createResult());
     QString stmt(QLatin1String("show index from %1;"));
     QSqlRecord fil = record(tablename);
@@ -1353,7 +1349,6 @@ QSqlIndex QMYSQLDriver::primaryIndex(const QString& tablename) const
         }
     }
 
-    d->preparedQuerysEnabled = prepQ;
     return idx;
 }