[Bug 84171] Re: compressing already compressed files should be avoided

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** Changed in: debhelper
       Status: New => Fix Released

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https://bugs.launchpad.net/bugs/84171

Title:
  compressing already compressed files should be avoided

Status in debhelper:
  Fix Released
Status in “debhelper” package in Ubuntu:
  Opinion

Bug description:
  Binary package hint: debhelper

  Noticed on the texlive documentation, but many other packages show the
  same problem.

  All the PDF documentation is gzipped.  This happens because
  dh_compress is applied as the debian guideline say that
  "documentation" should be compressed...

  Apparently, this is not very sensible:

  1) PDF is itself a compressed format... gzipping PDF files saves almost
  no space.  The only case where it saves space is when the original PDF
  was not properly compressed.  However, there are excellent tools for
  compressing PDF files without putting them in a non-pdf envelope.  For
  instance, see the PDF compress utility in the multivalent PDF tools.

  2) pdf.gz files cannot be opened directly with acrobat reader or kpdf or xpdf...
  they need to be decompressed somewhere and then opened... and eventually
  one needs to get rid of the uncompressed document... This is just an annoyance to many users.
  True, we have zxpdf... nonetheless why should one be compelled to use it when there are also other fine tools for dealing with pdf files?
  Also, for new users, not accustomed to the command line, the most natural thing to do is to explore documentation directories with a file manager (say konqueror). Indeed they find it disorienting not to be able to open the documentation by simply clicking on the doc files.

  3) in any case, hard disk space is nowadays is cheap... compressing
  documentation that already has compact formats saves little in space or
  cost, but wastes time...  If one has space, then non gzipped
  PDFs is better.  If one has no space, probably he would not
  install documentation at all.

  please do not gzip PDF files nor any file format that already includes
  (reasonable) compression.  It is also a matter of elegance.  If we
  accept the idea that compressing something that is already compressed
  makes sense, the day when someone invents a pdf-like format with
  better compression than gzip we might end up just slowing things down
  and enlarging files by adding a useless gzip compression envelope.

  I understand that the debian guidelines were probably born when most docs were in postscript (and in that case adding compression through a gzip envelope made great sense!)...
  however with pdf docs things are now different (and even for postscript documentation, the best thing to do now would probably be to compress it by a conversion to pdf, not by gzipping).
  If debian is reluctant to updating its guidelines, ubuntu might possibly open the way.

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