Don't include interpreter variable unless used

This adds an #ifdef around this variable, so that it isn't defined
unless used.

Spotted by Daniel Dragan.

1 files changed, 2 insertions, 0 deletions

diff --git a/sv.c b/sv.c
index 1856ba37c1..1090384cd8 100644
--- a/sv.c
+++ b/sv.c
@@ -15236,7 +15236,9 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_in_utf8_CTYPE_locale = proto_perl->Iin_utf8_CTYPE_locale;
     PL_in_utf8_COLLATE_locale = proto_perl->Iin_utf8_COLLATE_locale;
     my_strlcpy(PL_locale_utf8ness, proto_perl->Ilocale_utf8ness, sizeof(PL_locale_utf8ness));
+#if defined(USE_ITHREADS) && ! defined(USE_THREAD_SAFE_LOCALE)
     PL_lc_numeric_mutex_depth = 0;
+#endif
     /* Unicode features (see perlrun/-C) */
     PL_unicode		= proto_perl->Iunicode;