[glib] Do not load systemwide giomodules during self-test

[Philip Withnall <pwithnall src gnome org>]

commit deeacce18a7b3c8a0d5ef7ff72fda4b8b1746a66
Author: Daniel Macks <dmacks netspace org>
Date:   Mon Nov 20 03:28:17 2017 -0500

    Do not load systemwide giomodules during self-test
    
    $libdir/gio/modules/*.so on the live build machine are supplied by
    third parties, so we should not look there while testing ourselves.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780309

 gio/tests/Makefile.am |    1 +
 gio/tests/meson.build |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gio/tests/Makefile.am b/gio/tests/Makefile.am
index a553958..71721e5 100644
--- a/gio/tests/Makefile.am
+++ b/gio/tests/Makefile.am
@@ -15,6 +15,7 @@ LDADD = \
 AM_CPPFLAGS = $(gio_INCLUDES) $(GLIB_DEBUG_FLAGS) -I$(top_builddir)/gio -I$(top_srcdir)/gio
 DEFS = -DG_LOG_DOMAIN=\"GLib-GIO\" -DTEST_SERVICES=\""$(abs_top_builddir)/gio/tests/services"\"
 AM_CFLAGS = $(GLIB_WARN_CFLAGS)
+AM_TESTS_ENVIRONMENT += GIO_MODULE_DIR=
 
 # -----------------------------------------------------------------------------
 #  Test programs buildable on all platforms
diff --git a/gio/tests/meson.build b/gio/tests/meson.build
index fb17cc4..21b0c2a 100644
--- a/gio/tests/meson.build
+++ b/gio/tests/meson.build
@@ -67,6 +67,7 @@ test_extra_programs = [
 test_env = [
   'G_TEST_SRCDIR=' + meson.current_source_dir(),
   'G_TEST_BUILDDIR=' + meson.current_build_dir(),
+  'GIO_MODULE_DIR=',
 ]
 
 test_c_args = [