[pdftex] Default extension in pdftex.def?

[Andreas Matthias]

Filenames with more than one dot cause problems with pdflatex
and the pdftex.def driver:

  \includegraphics{test.foo.bar.baz.pdf}
  ! LaTeX Error: Unknown graphics extension: .foo.bar.baz.pdf.

Such filenames do not cause problems, if used with latex and
the dvips.def driver, because this driver defines a default
rule:

  dvips.def:
   \@namedef{Gin at rule@*}#1{{eps}{\Gin at ext}{#1}}

If I add such a default rule in pdftex.def

  pdftex.def:
   \@namedef{Gin at rule@*}#1{{pdf}{\Gin at ext}{#1}}

things go well for me. Pdf, png, jpg and tif files are
recognized even with more than one dot in their filenames.

Is there a reason, why pdftex.def does not have a default
rule like dvips.def? Wouldn't it be usefull to add such
a default rule?

Regards
Andreas