Intro:
------

I've noticed that 'rpm' (rpm-4.11.0.1 on Fedora 19) is no more defining environment variable RPM_INSTALL_PREFIX[1] by default.

[1] http://www.rpm.org/max-rpm/s1-rpm-reloc-building-relocatable.html#AEN9694

Description:
------------

Previous version of 'rpm' (rpm-4.9.1.3 on Fedora 17) were always defining 
RPM_INSTALL_PREFIX* for %pre and %post installation scripts:
RPM_INSTALL_PREFIX and RPM_INSTALL_PREFIX0 are supposed to match Prefix:[2] tag line in the package SPEC file or --prefix[3][4] command line argument when asking rpm to relocate a package.

I've seen a misleading old message[5] on RPM mailing list stating that RPM_INSTALL_PREFIX was removed, but it's not.
I've found no ChangeLog/Release Note about change on RPM_INSTALL_PREFIX[6].


[2] http://www.rpm.org/max-rpm/s1-rpm-reloc-prefix-tag.html
[3] http://www.rpm.org/max-rpm/s1-rpm-install-additional-options.html#S2-RPM-INSTALL-PREFIX
[4] http://www.rpm.org/max-rpm/s1-rpm-reloc-building-relocatable.html#S2-RPM-RELOC-TEST-DRIVE
[5] http://thread.gmane.org/gmane.linux.redhat.rpm.devel/497
[6] Release Notes:
    http://rpm.org/wiki/Releases/4.11.1
    http://rpm.org/wiki/Releases/4.11.0.1
    http://rpm.org/wiki/Releases/4.11.0
    http://rpm.org/wiki/Releases/4.10.3.1
    http://rpm.org/wiki/Releases/4.10.3
    http://rpm.org/wiki/Releases/4.10.2
    http://rpm.org/wiki/Releases/4.10.1
    http://rpm.org/wiki/Releases/4.10.0

How to reproduce:
-----------------

I've used test package based on SPEC file[7] sent to a mailing list to report a bug against RPM_INSTALL_PREFIX.

I modified this SPEC file to:
 - report RPM_INSTALL_PREFIX{0..15}
 - have a file inside of it.
   Empty package doesn't get at all RPM_INSTALL_PREFIX, even on older rpm.

I was able to produce the following results:

- Fedora 17, rpm 4.9.1.3

  # rpm -i test-package-1.0-2.noarch.rpm
  pre - RPM_INSTALL_PREFIX = "/opt/test-package"
  pre - RPM_INSTALL_PREFIX0 = "/opt/test-package"
  ...
  post - RPM_INSTALL_PREFIX = "/opt/test-package"
  post - RPM_INSTALL_PREFIX0 = "/opt/test-package"
  ...

  # rpm -i --prefix=/usr/local test-package-1.0-2.noarch.rpm 
  pre - RPM_INSTALL_PREFIX = "/usr/local"
  pre - RPM_INSTALL_PREFIX0 = "/usr/local"
  ...
  post - RPM_INSTALL_PREFIX = "/usr/local"
  post - RPM_INSTALL_PREFIX0 = "/usr/local"
  ...

- Fedora 19, rpm 4.11.0.1

  # rpm -i test-package-1.0-2.noarch.rpm
  pre - RPM_INSTALL_PREFIX = ""
  pre - RPM_INSTALL_PREFIX0 = ""
  ...
  post - RPM_INSTALL_PREFIX = ""
  post - RPM_INSTALL_PREFIX0 = ""

  # rpm -i --prefix=/usr/local test-package-1.0-2.noarch.rpm
  pre - RPM_INSTALL_PREFIX = "/usr/local"
  pre - RPM_INSTALL_PREFIX0 = "/usr/local"
  ...
  post - RPM_INSTALL_PREFIX = "/usr/local"
  post - RPM_INSTALL_PREFIX0 = "/usr/local"


On Fedora 19, without --prefix, RPM_INSTAL_PREFIX is not set.

[7] http://www.redhat.com/archives/rpm-list/2003-May/msg00486.html


Git bisect:
-----------

I've use git bisect with a custom script to locate a possible commit that change the RPM_INSTALL_PREFIX behavor.

Git bisect returns following commit[8]:

  5d3018c4ed476b1b7ac18e2573af517f872cb303 is the first bad commit
  commit 5d3018c4ed476b1b7ac18e2573af517f872cb303
  Author: Panu Matilainen <pmatilai>
  Date:   Tue Oct 2 16:17:05 2012 +0300

      Dont bother with rpmRelocateFileList() if relocations have been specified
    
      - rpmRelocateFileList() doesn't modify anything when no relocations
        are to be done, but what it does is not exactly free, unnecessarily
        calling it is dumb.

[8] http://rpm.org/gitweb?p=rpm.git;a=commitdiff;h=5d3018c4ed476b1b7ac18e2573af517f872cb303


Summarize:
----------

I think 'rpm' should define RPM_INSTALL_PREFIX if a prefix is defined in the SPEC file. It's looking like a regression.

Regards.