Qt Quick Compiler regression on iOS in 5.7.0

There seems to be a pretty nasty regression in the Qt Quick Compiler specific to iOS causing code to no longer compile. This happens with QT 5.7.0 but does not not seem to affect 5.6.x and older.

This can be reproduced in a number of ways. A pretty trivial example is to create a blank project on iOS, enable the qtquickcompiler and add the following line to your project. It doesn't really matter where:

property int time: 24 * 60 * 60 * 1000

This will result in the following assert during compilation:

/5.7/ios/bin/qtquickcompiler --resource=/untitled35/qml.qrc ../untitled35/main.qml .qtquickcompiler/main_qml.cpp
ASSERT: "endptr - target.data() <= length - eSign -1" in file ../../corelib/tools/qlocale_tools.cpp, line 227
make[1]: *** [.qtquickcompiler/main_qml.cpp] Abort trap: 6

It seems to be caused by using any moderately large numbers indicating some overflow bug. Note that these numbers are still well within the supported precision and should anyway not cause the compiler to fail.

Another expression that cause the same compilation error is this:

Math.round(1000000 * Math.random())

This can be reduced further down to a QtCore-only testcase:

Use main.cpp:

#include <QDebug>
#include <QCoreApplication>
#include <QByteArray>

int main(int argc, char **argv)
{
    QCoreApplication app(argc, argv);

    qDebug() << QByteArray::number(86400000, 'g', 6);

    return 0;
}

and a .pro file with this:

TEMPLATE = app
QT = bootstrap-private
SOURCES += main.cpp