don't augment PATH in TESTS_ENVIRONMENT

[Bruno Haible]

Hi Jim,

It is not possible to portably augment the same environment variable twice
in TESTS_ENVIRONMENT.

Witness: The shell command
       foo=a:$foo foo=b:$foo sh -c 'echo $foo'
prints
  b:a:  in ksh, OpenBSD /bin/sh
  a:b:  in Solaris 8 /bin/sh
  b:    in NetBSD /bin/sh and dash
and in bash 3.2.39 it's even weirder:
  b:a:  the first time,
  b:    the second time

  $ foo=a:$foo foo=b:$foo sh -c 'echo $foo'
  b:a:
  $ foo=a:$foo foo=b:$foo sh -c 'echo $foo'
  b:

As a consequence, since there are many modules, no gnulib module should
augment PATH in TESTS_ENVIRONMENT. If two of them do that, you get a collision.
Or if one of them does this, and the program's Makefile.am does it as well
(like recommended in tests/init.sh), you get a collision.

Conclusion: Only the program's Makefile.am is allowed to do this.


Here are proposed patches to fix this in these two commits:

2009-08-03  Joel E. Denny  <address@hidden>

        update-copyright: fix bug for 2-digit last year and add tests
        * build-aux/update-copyright: Fix bug.
        Use UPDATE_COPYRIGHT_YEAR from environment as current year if
        specified.
        * modules/update-copyright-tests: New
        * tests/test-update-copyright.sh: New.

<http://lists.gnu.org/archive/html/bug-gnulib/2008-05/msg00010.html>
2008-05-01  Jim Meyering  <address@hidden>

        vc-list-files: make the stand-alone gnulib test work
        * modules/vc-list-files-tests (configure.ac):
        Define and AC_SUBST abs_aux_dir.
        (Makefile.am) [TESTS_ENVIRONMENT]: Rather than passing
        $(abs_top_srcdir) to each script and having each of them
        duplicate the work of setting PATH, set PATH here, using
        the new variable, abs_aux_dir instead.
        * tests/test-vc-list-files-cvs.sh: Don't set PATH here.
        * tests/test-vc-list-files-git.sh: Likewise.
        Reported by Bruno Haible.


2010-09-04  Bruno Haible  <address@hidden>

        Don't augment PATH in TESTS_ENVIRONMENT.
        * modules/update-copyright-tests (Makefile.am): In TESTS_ENVIRONMENT,
        set abs_aux_dir instead of augmenting PATH.
        * modules/vc-list-files-tests (Makefile.am): Likewise.
        * tests/test-update-copyright.sh: Augment PATH here.
        * tests/test-vc-list-files-cvs.sh: Augment PATH here, through
        path_prepend_.
        * tests/test-vc-list-files-git.sh: Likewise.

--- modules/update-copyright-tests.orig Sat Sep  4 12:12:10 2010
+++ modules/update-copyright-tests      Sat Sep  4 12:06:32 2010
@@ -9,4 +9,4 @@
 
 Makefile.am:
 TESTS += test-update-copyright.sh
-TESTS_ENVIRONMENT += PATH='$(abs_aux_dir)'$(PATH_SEPARATOR)"$$PATH"
+TESTS_ENVIRONMENT += abs_aux_dir='$(abs_aux_dir)'
--- modules/vc-list-files-tests.orig    Sat Sep  4 12:12:10 2010
+++ modules/vc-list-files-tests Sat Sep  4 12:06:34 2010
@@ -12,4 +12,4 @@
 Makefile.am:
 TESTS += test-vc-list-files-git.sh
 TESTS += test-vc-list-files-cvs.sh
-TESTS_ENVIRONMENT += PATH='$(abs_aux_dir)'$(PATH_SEPARATOR)"$$PATH"
+TESTS_ENVIRONMENT += abs_aux_dir='$(abs_aux_dir)'
--- tests/test-update-copyright.sh.orig Sat Sep  4 12:12:10 2010
+++ tests/test-update-copyright.sh      Sat Sep  4 12:11:49 2010
@@ -27,6 +27,9 @@
   compare() { cmp "$@"; }
 fi
 
+# Ensure the update-copyright program gets found.
+PATH=$abs_aux_dir:$PATH
+
 TMP_BASE=update-copyright.test
 trap 'rm -f $TMP_BASE*' 0 1 2 3 15
 
--- tests/test-vc-list-files-cvs.sh.orig        Sat Sep  4 12:12:10 2010
+++ tests/test-vc-list-files-cvs.sh     Sat Sep  4 12:11:51 2010
@@ -17,7 +17,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 : ${srcdir=.}
-. "$srcdir/init.sh"; path_prepend_ .
+. "$srcdir/init.sh"; path_prepend_ $abs_aux_dir .
 
 tmpdir=vc-cvs
 repo=`pwd`/$tmpdir/repo
--- tests/test-vc-list-files-git.sh.orig        Sat Sep  4 12:12:10 2010
+++ tests/test-vc-list-files-git.sh     Sat Sep  4 12:11:51 2010
@@ -17,7 +17,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 : ${srcdir=.}
-. "$srcdir/init.sh"; path_prepend_ .
+. "$srcdir/init.sh"; path_prepend_ $abs_aux_dir .
 
 tmpdir=vc-git-$$
 GIT_DIR= GIT_WORK_TREE=; unset GIT_DIR GIT_WORK_TREE