Update gnulib to a3a946f670718d0dee5a7425ad5ac0a29fb46ea1wip-gnulib-update

This fixes https://lists.gnu.org/archive/html/guile-devel/2021-04/msg00009.html

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/mbtowc-lock.h b/lib/mbtowc-lock.h
index 320613eae..093951713 100644
--- a/lib/mbtowc-lock.h
+++ b/lib/mbtowc-lock.h
@@ -32,7 +32,17 @@ mbtowc_unlocked (wchar_t *pwc, const char *p, size_t m)
 /* Prohibit renaming this symbol.  */
 #undef gl_get_mbtowc_lock
 
-#if defined _WIN32 && !defined __CYGWIN__
+#if GNULIB_MBRTOWC_SINGLE_THREAD
+
+/* All uses of this function are in a single thread.  No locking needed.  */
+
+static int
+mbtowc_with_lock (wchar_t *pwc, const char *p, size_t m)
+{
+  return mbtowc_unlocked (pwc, p, m);
+}
+
+#elif defined _WIN32 && !defined __CYGWIN__
 
 extern __declspec(dllimport) CRITICAL_SECTION *gl_get_mbtowc_lock (void);