The data is not random. I can add the data manually and I get the effect I want, but if I try to use that same data to patch the file in question, I cannot apply the patch.

I don't know how to use git and haven't needed it so far, I'll look into it.

The rpm patch that won't apply is one I emailed to you earlier; sailfishos-patch-transparent-email-background, install and try to apply, it fails. The patch file is patching 4 different files, but only the htmlViewer.css is causing problems and I don't know how to get round it.