[REG: 4.8->5.4]: When painting lines to a printer it can will take a lot of time to paint

When painting lines to a printer it can will take a lot of time to paint. This is only the case when painting directly to a printer, if the lines are painted to a QImage first instead with the same dimensions then it will paint quickly and the subsequent image is also painted quickly.

In the example attached, just run it and it will prompt for a printer to print to and then the console output will give an indication as to the time taken.