Error with placeholder order in QString with arg

If I reorder my “%”-placeholders in QString, arg can’t process them correctly. It seems like the first digit (0-9) of placeholder %2 gets eaten..
Code below demonstrates the issue:

void UnitTests::test_stringArgs()

Unknown macro: { QString expected = QString("_Area52_"); QString test1 = QString("_%1%2%3_").arg("Area").arg(5).arg(2); QString test2 = QString("_%1_%3_%2_").arg("Area").arg(2).arg(5); QString test3 = QString("_%1%3%2_").arg("Area").arg(2); QString test4 = QString("_%1%3%2_").arg("Area").arg(2).arg(5); QCOMPARE(expected, test1); QCOMPARE(QString("_Area_5_2_"), test2); QCOMPARE(QString("_Area%32_"), test3); QCOMPARE(expected, test4); }

FAIL! on line 13: test_stringArgs() Compared values are not the same
Actual (expected): Area52
Expected (test4): Area5

QString test4 = QString("%1%3%2").arg("Area").arg(20).arg(50);
QString test4m = QString("%1%2%3").arg("Area").arg(50).arg(20);
Q_ASSERT (test4 == test4m);

Assert fails due to:
+ test4 "Area500" QString
+ test4m "Area5020" QString@

This happens on Qt 4.8.5 and Qt 5.2. People in the thread linked below describe other versions and platforms

see thread on this issue: http://qt-project.org/forums/viewthread/52254/#215973