[glib] build: Use AM_TESTS_ENVIRONMENT rather than TESTS_ENVIRONMENT

[Philip Withnall <pwithnall src gnome org>]

commit a05b64a0cb234fffad12af0ca052296a1bae4a85
Author: Philip Withnall <withnall endlessm com>
Date:   Tue May 23 13:28:19 2017 +0100

    build: Use AM_TESTS_ENVIRONMENT rather than TESTS_ENVIRONMENT
    
    TESTS_ENVIRONMENT is reserved for the user to be able to set when
    running the tests. AM_TESTS_ENVIRONMENT is for the tests’ Makefile to
    set itself.
    
    https://www.gnu.org/software/automake/manual/html_node/Scripts_002dbased-Testsuites.html
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=782996

 glib-tap.mk                |    2 +-
 tests/Makefile.am          |    2 +-
 tests/gobject/Makefile.am  |    2 +-
 tests/refcount/Makefile.am |    2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/glib-tap.mk b/glib-tap.mk
index 9a3a445..5f25b62 100644
--- a/glib-tap.mk
+++ b/glib-tap.mk
@@ -1,6 +1,6 @@
 # GLIB - Library of useful C routines
 
-TESTS_ENVIRONMENT= \
+AM_TESTS_ENVIRONMENT= \
        G_TEST_SRCDIR="$(abs_srcdir)"           \
        G_TEST_BUILDDIR="$(abs_builddir)"       \
        G_DEBUG=gc-friendly                     \
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 72af39d..4623150 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -79,7 +79,7 @@ dist_test_data = \
 check_PROGRAMS += $(installed_test_programs) $(installed_test_extra_programs)
 check_SCRIPTS += $(installed_test_scripts)
 TESTS += $(installed_test_programs) $(dist_uninstalled_test_extra_scripts)
-TESTS_ENVIRONMENT = \
+AM_TESTS_ENVIRONMENT = \
        G_TEST_SRCDIR=$(abs_srcdir)                             \
        G_TEST_BUILDDIR=$(abs_builddir)                         \
        LIBCHARSET_ALIAS_DIR=$(top_builddir)/glib/libcharset    \
diff --git a/tests/gobject/Makefile.am b/tests/gobject/Makefile.am
index 16f2827..656941d 100644
--- a/tests/gobject/Makefile.am
+++ b/tests/gobject/Makefile.am
@@ -34,7 +34,7 @@ noinst_PROGRAMS += \
 # This will cause them to be built even if installed tests are disabled.
 check_PROGRAMS += $(installed_test_programs) $(installed_test_extra_programs)
 TESTS += $(installed_test_programs)
-TESTS_ENVIRONMENT = \
+AM_TESTS_ENVIRONMENT = \
        LIBCHARSET_ALIAS_DIR=$(top_builddir)/glib/libcharset    \
        MALLOC_CHECK_=2                                         \
        MALLOC_PERTURB_=$$(($${RANDOM:-256} % 256))
diff --git a/tests/refcount/Makefile.am b/tests/refcount/Makefile.am
index f9a98dc..6315c6e 100644
--- a/tests/refcount/Makefile.am
+++ b/tests/refcount/Makefile.am
@@ -20,7 +20,7 @@ TESTS += \
        signal4                                 \
        $(NULL)
 
-TESTS_ENVIRONMENT = srcdir=$(srcdir) \
+AM_TESTS_ENVIRONMENT = srcdir=$(srcdir) \
        LIBCHARSET_ALIAS_DIR=$(top_builddir)/glib/libcharset
 
 signal1_SOURCES = signals.c