Force en_US locale for certain tests.

--- a/libs/maildrop/Makefile.am
+++ b/libs/maildrop/Makefile.am
@@ -82,17 +82,22 @@
 	$(MAKE) run-testsuite-mailbot-old
 
 run-testsuite: testsuite
+if HAS_EN_US
 	VALGRIND="`which valgrind 2>/dev/null`"; export VALGRIND; \
 		@SHELL@ ./testsuite >testsuite.diff || exit 1; \
 		sed '/^Message envelope sender/d' <testsuite.diff | \
 		diff -U 3 $(srcdir)/testsuite.txt.idn - || exit 1; \
 		rm -f testsuite.diff
+endif
 
 run-testsuite2:
+if HAS_EN_US
-	VALGRIND="`which valgrind 2>/dev/null`"; export VALGRIND; \
+	VALGRIND=""; export VALGRIND; \
 		@SHELL@ $(srcdir)/testsuite2
+endif
 
 run-testsuite-mailbot: testsuite.mailbot
+if HAS_EN_US
 	VALGRIND="`which valgrind 2>/dev/null`"; export VALGRIND; \
 		VALGRIND_EXTRA_OPTS="--leak-check=full"; \
 		export VALGRIND_EXTRA_OPTS; \
@@ -101,14 +106,17 @@
 		@SHELL@ $(srcdir)/testsuite.mailbot >testsuite.diff
 	diff -U 3 $(srcdir)/testsuite.mailbot.txt testsuite.diff
 	rm -f mailbot.tst testsuite.diff
+endif
 
 run-testsuite-mailbot-old: testsuite.mailbot
+if HAS_EN_US
 	VALGRIND="`which valgrind 2>/dev/null`"; export VALGRIND; \
 		rm -f ./mailbot.tst; \
 		ln -s mailbot-old mailbot.tst; \
 		@SHELL@ $(srcdir)/testsuite.mailbot >testsuite.diff
 	diff -U 3 $(srcdir)/testsuite.mailbot.txt testsuite.diff
 	rm -f mailbot.tst testsuite.diff
+endif
 
 noinst_DATA=maildrop.html maildrop.1 maildropfilter.html maildropfilter.7 \
 	maildropgdbm.html maildropgdbm.7
--- maildrop-3.0.0/libs/maildrop/configure.ac
+++ maildrop-3.0.0/libs/maildrop/configure.ac
@@ -202,6 +202,15 @@
 AC_DEFINE_UNQUOTED(MAXLONGSIZE, $MAXLONGSIZE,
 				[ Maximum character size of a long ])
 
+dnl check for en_US locale
+check_en_US() {
+	locale -a | grep en_US.utf8 > /dev/null
+	return $?
+}
+AC_MSG_CHECKING([for en_US.utf8])
+AM_CONDITIONAL([HAS_EN_US], [check_en_US])
+AM_COND_IF([HAS_EN_US],[AC_MSG_RESULT([yes])],[AC_MSG_RESULT([not found])])
+
 dnl Checks for library functions.
 
 AC_FUNC_CLOSEDIR_VOID
--- a/libs/rfc2045/Makefile.am
+++ b/libs/rfc2045/Makefile.am
@@ -97,6 +97,7 @@
 endif
 
 check-am:
+if HAS_EN_US
 	@SHELL@ $(srcdir)/testsuite | diff -U 3 $(srcdir)/testsuite.txt.idn -
 	@SHELL@ $(srcdir)/testsuitemm | diff -U 3 $(srcdir)/testsuitemm.txt -
 	@SHELL@ $(srcdir)/testrfc3676parsersuite | diff -U 3 $(srcdir)/testrfc3676parsersuite.txt -
@@ -107,3 +108,4 @@
 		valgrind --tool=memcheck --leak-check=yes --error-exitcode=1 ./testrfc6533parser ; \
 		valgrind --tool=memcheck --leak-check=yes --error-exitcode=1 ./testsuitecpp ; \
 		valgrind --tool=memcheck --leak-check=yes --error-exitcode=1 ./testsuitecpp2
+endif
--- maildrop-3.0.0/libs/rfc2045/configure.ac
+++ maildrop-3.0.0/libs/rfc2045/configure.ac
@@ -60,6 +60,15 @@
 dnl Checks for library functions.
 AC_CHECK_FUNCS(setlocale)
 
+dnl check for en_US locale
+check_en_US() {
+	locale -a | grep en_US.utf8 > /dev/null
+	return $?
+}
+AC_MSG_CHECKING([for en_US.utf8])
+AM_CONDITIONAL([HAS_EN_US], [check_en_US])
+AM_COND_IF([HAS_EN_US],[AC_MSG_RESULT([yes])],[AC_MSG_RESULT([not found])])
+
 AC_ARG_WITH(package, [], package="$withval",
 	[
 		package="$PACKAGE"