make distcheck drops precious vars

[Ralf Corsepius]

Hi,

with automake-1.7.2, ""make distcheck" seems to drop autoconf's precious
vars.

This breaks "make distcheck" for packages which require special settings
to be buildable in a user environment.

The tarball below contains a minimized hypothetical example to
demonstrate the problem:
# ./configure CPPFLAGS=-D__foobar__
# make
[works]
# make dist
[works]
# make distcheck
[aborts due to CPPFLAGS having been lost]

In my actual case, I need to set up CPPFLAGS to point to the include
directory of a prerequisite package outside of the compiler's default
search path. However, make distcheck drops CPPFLAGS :(

Ralf

automake-bug-4.0.tar.bz2
Description: application/bzip