From 8053ae4030b4342f73a08b9870ccd19189ae401d Mon Sep 17 00:00:00 2001

From: Mark Brand <mabrand@mabrand.nl>

Date: Thu, 7 Mar 2013 11:52:52 +0100

Subject: [PATCH 4/4] postgresql driver: escape backslashes only when server

 requires it

Task-number: QTBUG-30076

Change-Id: I408cda941884f01484d0edfa82c91fc19cb8718c

Reviewed-by: Israel Lins Albuquerque <israelins85@yahoo.com.br>

Reviewed-by: Sergey Blagodarin

Reviewed-by: Andy Shaw <andy.shaw@digia.com>

Reviewed-by: Andras Mantia <andras@kdab.com>

(cherry picked from qtbase/e3c5351d06ce8a12f035cd0627356bc64d8c334a)

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

---

 src/sql/drivers/psql/qsql_psql.cpp | 38 +++++++++++++++++++++++++++++++++-----

 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/sql/drivers/psql/qsql_psql.cpp b/src/sql/drivers/psql/qsql_psql.cpp

index 51ddce0..c2a127c 100644

--- a/src/sql/drivers/psql/qsql_psql.cpp

+++ b/src/sql/drivers/psql/qsql_psql.cpp

@@ -120,7 +120,16 @@ inline void qPQfreemem(void *buffer)

 class QPSQLDriverPrivate

 {

 public:

-    QPSQLDriverPrivate(QPSQLDriver *qq) : q(qq), connection(0), isUtf8(false), pro(QPSQLDriver::Version6), sn(0), pendingNotifyCheck(false) {}

+    QPSQLDriverPrivate(QPSQLDriver *qq)

+      : q(qq),

+        connection(0),

+        isUtf8(false),

+        pro(QPSQLDriver::Version6),

+        sn(0),

+        pendingNotifyCheck(false),

+        hasBackslashEscape(false)

+    { }

+

     QPSQLDriver *q;

     PGconn *connection;

     bool isUtf8;

@@ -128,6 +137,7 @@ public:

     QSocketNotifier *sn;

     QStringList seid;

     mutable bool pendingNotifyCheck;

+    bool hasBackslashEscape;

     void appendTables(QStringList &tl, QSqlQuery &t, QChar type);

     PGresult * exec(const char * stmt) const;

@@ -135,6 +145,7 @@ public:

     QPSQLDriver::Protocol getPSQLVersion();

     bool setEncodingUtf8();

     void setDatestyle();

+    void detectBackslashEscape();

 };

 void QPSQLDriverPrivate::appendTables(QStringList &tl, QSqlQuery &t, QChar type)

@@ -636,6 +647,23 @@ void QPSQLDriverPrivate::setDatestyle()

     PQclear(result);

 }

+void QPSQLDriverPrivate::detectBackslashEscape()

+{

+    // standard_conforming_strings option introduced in 8.2

+    // http://www.postgresql.org/docs/8.2/static/runtime-config-compatible.html

+    if (pro < QPSQLDriver::Version82) {

+        hasBackslashEscape = true;

+    } else {

+        hasBackslashEscape = false;

+        PGresult* result = exec(QLatin1String("SELECT '\\\\' x"));

+        int status = PQresultStatus(result);

+        if (status == PGRES_COMMAND_OK || status == PGRES_TUPLES_OK)

+            if (QString::fromLatin1(PQgetvalue(result, 0, 0)) == QLatin1String("\\"))

+                hasBackslashEscape = true;

+        PQclear(result);

+    }

+}

+

 static QPSQLDriver::Protocol qMakePSQLVersion(int vMaj, int vMin)

 {

     switch (vMaj) {

@@ -742,6 +770,7 @@ QPSQLDriver::QPSQLDriver(PGconn *conn, QObject *parent)

     d->connection = conn;

     if (conn) {

         d->pro = d->getPSQLVersion();

+        d->detectBackslashEscape();

         setOpen(true);

         setOpenError(false);

     }

@@ -842,6 +871,7 @@ bool QPSQLDriver::open(const QString & db,

     }

     d->pro = d->getPSQLVersion();

+    d->detectBackslashEscape();

     d->isUtf8 = d->setEncodingUtf8();

     d->setDatestyle();

@@ -1228,12 +1258,10 @@ QString QPSQLDriver::formatValue(const QSqlField &field, bool trimStrings) const

             }

             break;

         case QVariant::String:

-        {

-            // Escape '\' characters

             r = QSqlDriver::formatValue(field, trimStrings);

-            r.replace(QLatin1String("\\"), QLatin1String("\\\\"));

+            if (d->hasBackslashEscape)

+                r.replace(QLatin1String("\\"), QLatin1String("\\\\"));

             break;

-        }

         case QVariant::Bool:

             if (field.value().toBool())

                 r = QLatin1String("TRUE");

-- 

1.8.3.1