[tex-live] pretest: epstopdf overwrites existing files

[Karl Berry]

      (a) `foo-epstopdf.png'.

Yeah.  I was thinking that was still ok, because it is the epstopdf
package that is doing it.  But I realize it has its confusions, too.
      
      \epstopdfsetup{suffix=\SourceExt-converted-to}

That seems ok.  Maybe we can omit the -to, to make it a little shorter.
Just foo.{eps,png,...}-converted.pdf still seems ok?  Either way.

    However, what is to do, if a PDF file exists (without suffix)?
    Should it be used instead of generating a PDF file (with suffix)?

Yes.

    To solve this, I have added option `prefersuffix', that controls
    the behaviour:
      prefersuffix=true ==> always use the generated name with suffix
      prefersuffix=false ==> use the file with name without suffix

    (3) Default settings. Now, that files aren't overwritten, I think, I can
    dare to change the default, e.g. to
      prepend,
      update,
      suffix=...,% [see (1)]
      prefersuffix=false

    What do you think?

My understanding of the results are that:

1) user has both foo.eps and foo.pdf (created in whatever way): Their
   foo.pdf gets used.  Nothing is generated.

2) user has only foo.eps: foo.SUFFIX.pdf gets generated, and used.
   foo.SUFFIX.pdf is not regenerated unless foo.eps changes.

3) if the user does some manual tweaks on foo.SUFFIX.pdf and copies it
   to foo.pdf, then once again foo.pdf will be used (and not overwritten).

Is that correct?

Thanks,
Karl