diff --git a/src/svg/qsvghandler.cpp b/src/svg/qsvghandler.cpp

index 77af8161..7378e962 100644

--- a/src/svg/qsvghandler.cpp

+++ b/src/svg/qsvghandler.cpp

@@ -746,16 +746,17 @@ static QVector<qreal> parsePercentageList(const QChar *&str)

 static QString idFromUrl(const QString &url)

 {

     QString::const_iterator itr = url.constBegin();

-    while ((*itr).isSpace())

+    QString::const_iterator end = url.constEnd();

+    while (itr != end && (*itr).isSpace())

         ++itr;

-    if ((*itr) == QLatin1Char('('))

+    if (itr != end && (*itr) == QLatin1Char('('))

         ++itr;

-    while ((*itr).isSpace())

+    while (itr != end && (*itr).isSpace())

         ++itr;

-    if ((*itr) == QLatin1Char('#'))

+    if (itr != end && (*itr) == QLatin1Char('#'))

         ++itr;

     QString id;

-    while ((*itr) != QLatin1Char(')')) {

+    while (itr != end && (*itr) != QLatin1Char(')')) {

         id += *itr;

         ++itr;

     }