diff --git a/libcxx/include/locale b/libcxx/include/locale
--- a/libcxx/include/locale
+++ b/libcxx/include/locale
@@ -2891,6 +2891,10 @@
                                             unique_ptr<char_type, void(*)(void*)>& __wb,
                                             char_type*& __wn, char_type* __we)
 {
+    if (__b == __e) {
+        __err |= ios_base::failbit;
+        return false;
+    }
     const unsigned __bz = 100;
     unsigned __gbuf[__bz];
     unique_ptr<unsigned, void(*)(void*)> __gb(__gbuf, __do_nothing);
diff --git a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_en_US.pass.cpp b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_en_US.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_en_US.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_en_US.pass.cpp
@@ -721,6 +721,17 @@
             assert(err == std::ios_base::failbit);
         }
     }
+    {
+      // test for err
+      const my_facet f(1);
+      std::string v = "1.23";
+      typedef cpp17_input_iterator<const char*> I;
+      long double ex = -1L;
+      std::ios_base::iostate err = std::ios_base::goodbit;
+      f.get(I(v.data()), I(v.data()), false, ios, err, ex);
+      assert(err == (std::ios_base::failbit | std::ios_base::eofbit));
+      assert(ex == -1L);
+    }
 
   return 0;
 }
diff --git a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_string_en_US.pass.cpp b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_string_en_US.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_string_en_US.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_string_en_US.pass.cpp
@@ -729,6 +729,17 @@
             assert(ex == L"");
         }
     }
+    {
+      // test for err
+      const my_facet f(1);
+      std::string v = "1.23";
+      typedef cpp17_input_iterator<const char*> I;
+      std::string ex = "NULL";
+      std::ios_base::iostate err = std::ios_base::goodbit;
+      f.get(I(v.data()), I(v.data()), false, ios, err, ex);
+      assert(err == (std::ios_base::failbit | std::ios_base::eofbit));
+      assert(ex == "NULL");
+    }
 
   return 0;
 }