bug#35490: Creating a ./configure diff against gzip-1.9

[Ilya Leoshkevich]

Hi,

I’m trying to backport IBM Z patches to gzip version 1.9.  The code
changes themselves apply without problems, however, I also need to
create a diff for configure and other generated build files.  If I just
use whatever distro I have at hand for this, there will be a lot of
noise from autoconf and automake version mismatch, so I'm trying to
figure out which exact versions were used for the 1.9 release.

I'm observing a few surprising things, and it would be great if someone
could help me resolve them and get to the point where I can reproduce
the 1.9 release from git sources:


- The released ./Makefile.in contains:

    distdir-am: $(DISTFILES)

which means that automake version used contained the commit ac47c2:
"make dist" did not depend on $(BUILT_SOURCES) from Nov 28 2017.

At the same time, the released ./build-aux/ar-lib contains:

    # Copyright (C) 2010-2015 Free Software Foundation, Inc.

which means that automake must have been older than commit d8add5:
maint: Update copyright years to 2017. from Mar 2 2017.

This is clearly impossible, and the only other version indication that I
could find is:

    Makefile.in generated by automake 1.15a

which does not really help, since this correspond to a lot of commits.
Can it be that a private branch was used?


- The released ./configure contains:

    Generated by GNU Autoconf 2.69.193-8974

However, 8974 is not an existing commit id.  Again, would it be correct
to assume that this is coming from a private branch?  The closest
version I could come up with is 2.69.193-dfb0.


- The am__DIST_COMMON list in the released ./Makefile.in contains
  build-aux/ar-lib.

However, there is no AM_PROG_AR or similar macros in the released
./configure.ac.  When I do `make dist`, it is not generated.  Where is
it supposed to come from?


- The released ./aclocal.m4 contains:

    # po.m4 serial 24 (gettext-0.19)

However, the released ./configure.ac does not contain
AM_GNU_GETTEXT_VERSION - where is po.m4 coming from?


Best regards,
Ilya