[PATCH 28/32] tests: protect test libs against multiple inclusion

[Stefano Lattarini]

* t/ax/test-lib.sh, t/ax/am-test-lib.sh: Return early if already sourced.
Use the witness variables '$test_lib_sourced' and '$am_test_lib_sourced',
respectively, for this purpose.
* runtest.in, Makefile.am (AM_TESTS_ENVIRONMENT): Unset 'test_lib_sourced'
and 'am_test_lib_sourced', to avoid interferences from the environment.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 Makefile.am         | 2 ++
 t/ax/am-test-lib.sh | 4 ++++
 t/ax/test-lib.sh    | 4 ++++
 3 files changed, 10 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index 172347f..d255288 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -342,6 +342,8 @@ AM_TESTS_ENVIRONMENT = \
     am_test_prefer_config_shell \
     am_original_AUTOMAKE \
     am_original_ACLOCAL \
+    am_test_lib_sourced \
+    test_lib_sourced \
   ; do \
     eval test x"\$${$$v}" = x || unset $$v; \
   done;
diff --git a/t/ax/am-test-lib.sh b/t/ax/am-test-lib.sh
index aaa8df5..8a0e117 100644
--- a/t/ax/am-test-lib.sh
+++ b/t/ax/am-test-lib.sh
@@ -19,6 +19,10 @@
 ###  IMPORTANT NOTE: keep this file 'set -e' clean.  ###
 ########################################################
 
+# Do not source several times.
+test ${am_test_lib_sourced-no} = yes && return 0
+am_test_lib_sourced=yes
+
 # A literal escape character.  Used by test checking colored output.
 esc=''
 
diff --git a/t/ax/test-lib.sh b/t/ax/test-lib.sh
index 60ffd98..9a530b1 100644
--- a/t/ax/test-lib.sh
+++ b/t/ax/test-lib.sh
@@ -19,6 +19,10 @@
 ###  IMPORTANT NOTE: keep this file 'set -e' clean.  ###
 ########################################################
 
+# Do not source several times.
+test ${test_lib_sourced-no} = yes && return 0
+test_lib_sourced=yes
+
 # CDPATH is evil if used in non-interactive scripts (and even more
 # evil if exported in the environment).
 CDPATH=; unset CDPATH
-- 
1.7.12.rc0