Test non-strictly null terminated arrays

Author: frederick-vs-ja

libcxx/test/std/utilities/format/format.functions/format_tests.h

@@ -3194,6 +3194,9 @@ void format_tests(TestFunction check, ExceptionTest check_exception) {
     // Contents after the embedded null character are discarded.
     CharT buffer[] = {CharT('a'), CharT('b'), CharT('c'), 0, CharT('d'), CharT('e'), CharT('f'), 0};
     check(SV("hello abc"), SV("hello {}"), buffer);
+    // Even when the last element of the array is not null character.
+    CharT buffer2[] = {CharT('a'), CharT('b'), CharT('c'), 0, CharT('d'), CharT('e'), CharT('f')};
+    check(SV("hello abc"), SV("hello {}"), buffer2);
   }
   {
     std::basic_string<CharT> data = STR("world");