QString arg( int, width, base, fill ) does not work if width != 0.

I was trying to create zero-filled hex strings (like sprintf( buf, "%02X", 123 )) and discovered that QString.arg(...) with a non-zero width and base 16 acts like sprintf( buf, "%.32f", 123 ):

Sample code:

QString ok = QString( "%1" ).arg( 123, 0, 16 );
QString ng = QString( "%1" ).arg( 123, 2, 16, '0' );

cerr << ok.toStdString( ) << endl;
cerr << ng.toStdString( ) << endl;

Sample output:

7b
123.000000000000000000000000000000000000000000000000