2 files changed, 19 insertions, 2 deletions

diff --git a/lib/libc/locale/newlocale.3 b/lib/libc/locale/newlocale.3
index c7414be73d3a8..cc5043df8eb1d 100644
--- a/lib/libc/locale/newlocale.3
+++ b/lib/libc/locale/newlocale.3
@@ -26,7 +26,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
-.Dd September 17, 2011
+.Dd October 2, 2020
 .Dt NEWLOCALE 3
 .Os
 .Sh NAME
@@ -46,7 +46,20 @@ defines the components that the new locale will have set to the locale with the
 name specified in the
 .Fa locale
 parameter.
-Any other components will be inherited from
+Any components not specified in
+.Fa mask
+will be inherited from the locale referenced by
+.Fa base ,
+if
+.Fa base
+is not
+.Dv NULL .
+If the call is successful, the state of the locale referenced by
+.Fa base
+is unspecified, and it must not be accessed.
+The special locale
+.Dv LC_GLOBAL_LOCALE
+may not be specified for
 .Fa base .
 The
 .Fa mask
diff --git a/lib/libc/locale/xlocale.c b/lib/libc/locale/xlocale.c
index c1995179463e2..465172fe24ebe 100644
--- a/lib/libc/locale/xlocale.c
+++ b/lib/libc/locale/xlocale.c
@@ -251,6 +251,7 @@ static int dupcomponent(int type, locale_t base, locale_t new)
 
 locale_t newlocale(int mask, const char *locale, locale_t base)
 {
+	locale_t orig_base;
 	int type;
 	const char *realLocale = locale;
 	int useenv = 0;
@@ -263,6 +264,7 @@ locale_t newlocale(int mask, const char *locale, locale_t base)
 		return (NULL);
 	}
 
+	orig_base = base;
 	FIX_LOCALE(base);
 	copyflags(new, base);
 
@@ -297,6 +299,8 @@ locale_t newlocale(int mask, const char *locale, locale_t base)
 	if (0 == success) {
 		xlocale_release(new);
 		new = NULL;
+	} else if (base == orig_base) {
+		xlocale_release(base);
 	}
 
 	return (new);