[libvirt] [PATCH] build: avoid non-portable shell in test setup

[Eric Blake]

POSIX states that 'a=1; a=2 b=$a command' has unspecified results
for the value of $b visible within command.  In particular, on
BSD, this resulted in PATH not picking up the in-test ssh.

* tests/Makefile.am (lv_abs_top_builddir): New macro.
(path_add, TESTS_ENVIRONMENT): Use it to avoid referring to an
environment variable set previously within the same command line.
Reported by Matthias Bolte.
---

Spotted by inspection based on an IRC report; hopefully someone
on BSD can test if it actually makes a difference.

 tests/Makefile.am |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 43a4301..f4afcb9 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -259,13 +259,17 @@ TESTS += interfacexml2xmltest

 TESTS += cputest

-path_add = $$abs_top_builddir/daemon$(PATH_SEPARATOR)$$abs_top_builddir/tools$(PATH_SEPARATOR)$$abs_top_builddir/tests
-
 # NB, automake < 1.10 does not provide the real
 # abs_top_{src/build}dir or builddir variables, so don't rely
 # on them here. Fake them with 'pwd'
+# Also, BSD sh doesn't like 'a=b b=$$a', so we can't use an
+# intermediate shell variable, but must do all the expansion in make
+
+lv_abs_top_builddir=`cd '$(top_builddir)'; pwd`
+path_add = $(lv_abs_top_builddir)/daemon$(PATH_SEPARATOR)$(lv_abs_top_builddir)/tools$(PATH_SEPARATOR)$(lv_abs_top_builddir)/tests
+
 TESTS_ENVIRONMENT =				\
-  abs_top_builddir=`cd '$(top_builddir)'; pwd`	\
+  abs_top_builddir=$(lv_abs_top_builddir)	\
   abs_top_srcdir=`cd '$(top_srcdir)'; pwd`	\
   abs_builddir=`pwd`				\
   abs_srcdir=`cd '$(srcdir)'; pwd`		\
-- 
1.7.4.4