XXXdelta Add my_strftime8()

This is like plain my_strftime(), but additionally returns an indication
of the UTF-8ness of the returned string

embed.fnc

@@ -1417,7 +1417,12 @@ Ap	|PerlIO*|my_popen_list	|NN const char* mode|int n|NN SV ** args
 Apd	|void	|my_setenv	|NULLOK const char* nam|NULLOK const char* val
 m	|I32	|my_stat
 pX	|I32	|my_stat_flags	|NULLOK const U32 flags
-Adfp	|char *	|my_strftime	|NN const char *fmt|int sec|int min|int hour|int mday|int mon|int year|int wday|int yday|int isdst
+Adfp	|char *	|my_strftime	|NN const char *fmt|int sec|int min|int hour \
+				|int mday|int mon|int year|int wday|int yday \
+				|int isdst
+Adfp	|char *	|my_strftime8	|NN const char *fmt|int sec|int min|int hour \
+				|int mday|int mon|int year|int wday|int yday \
+				|int isdst|NULLOK int * utf8ness
 : Used in pp_ctl.c
 p	|void	|my_unexec
 CbDTPR	|UV	|NATIVE_TO_NEED	|const UV enc|const UV ch

embed.h

@@ -333,6 +333,7 @@
 #define my_setenv(a,b)		Perl_my_setenv(aTHX_ a,b)
 #define my_socketpair		Perl_my_socketpair
 #define my_strftime(a,b,c,d,e,f,g,h,i,j)	Perl_my_strftime(aTHX_ a,b,c,d,e,f,g,h,i,j)
+#define my_strftime8(a,b,c,d,e,f,g,h,i,j,k)	Perl_my_strftime8(aTHX_ a,b,c,d,e,f,g,h,i,j,k)
 #define my_strtod		Perl_my_strtod
 #define newANONATTRSUB(a,b,c,d)	Perl_newANONATTRSUB(aTHX_ a,b,c,d)
 #define newANONHASH(a)		Perl_newANONHASH(aTHX_ a)

ext/POSIX/POSIX.xs

@@ -3549,29 +3549,19 @@ strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)
 	{
 	    char *buf;
             SV *sv;
+            int is_utf8;
 
             /* allowing user-supplied (rather than literal) formats
              * is normally frowned upon as a potential security risk;
              * but this is part of the API so we have to allow it */
             GCC_DIAG_IGNORE_STMT(-Wformat-nonliteral);
-	    buf = my_strftime(SvPV_nolen(fmt), sec, min, hour, mday, mon, year, wday, yday, isdst);
+	    buf = my_strftime8(SvPV_nolen(fmt), sec, min, hour, mday, mon, year, wday, yday, isdst, &is_utf8);
             GCC_DIAG_RESTORE_STMT;
             sv = sv_newmortal();
 	    if (buf) {
                 STRLEN len = strlen(buf);
 		sv_usepvn_flags(sv, buf, len, SV_HAS_TRAILING_NUL);
-		if (       SvUTF8(fmt)
-                    || (   is_utf8_non_invariant_string((U8*) buf, len)
-#ifdef USE_LOCALE_TIME
-                        && _is_cur_LC_category_utf8(LC_TIME)
-#else   /* If can't check directly, at least can see if script is consistent,
-           under UTF-8, which gives us an extra measure of confidence. */
-
-                        && isSCRIPT_RUN((const U8 *) buf,
-                                        (const U8 *) buf + len,
-                                        TRUE) /* Means assume UTF-8 */
-#endif
-                )) {
+		if (SvUTF8(fmt) || is_utf8 == 2) {
 		    SvUTF8_on(sv);
 		}
             }

locale.c

@@ -4158,6 +4158,63 @@ S_my_langinfo_i(pTHX_
 
 #endif      /* USE_LOCALE */
 
+/*
+=for apidoc my_strftime8
+
+This is L</my_strftime> with an extra parameter, whose value on return
+indicates how to interpret the returned string:
+
+=over
+
+=item Z<>2
+
+The returned string should be interpreted as being encoded in UTF-8.
+
+=item Z<>1
+
+It is the caller's choice as to how to interpret the returned string.  It has
+the same representation when encoded in UTF-8 as when not.
+
+=item Z<>0
+
+Do not interpret the returned string as UTF-8.
+
+=back
+
+=cut
+*/
+
+char *
+Perl_my_strftime8(pTHX_ const char *fmt, int sec, int min, int hour, int mday,
+                         int mon, int year, int wday, int yday, int isdst,
+                         int * utf8ness)
+{
+    char * retval = my_strftime(fmt, sec, min, hour, mday, mon, year, wday,
+                                yday, isdst);
+
+    PERL_ARGS_ASSERT_MY_STRFTIME8;
+
+    if (utf8ness) {
+
+#ifdef USE_LOCALE_TIME
+        *utf8ness = get_locale_string_utf8ness_i(NULL, LC_TIME_INDEX_,
+                                                 retval, UTF8NESS_UNKNOWN);
+#else
+        *utf8ness = 1;
+#endif
+
+    }
+
+    DEBUG_Lv(PerlIO_printf(Perl_debug_log, "%s: %d: fmt=%s, retval=%s",
+                                           __FILE__,  __LINE__, fmt, retval);
+             if (utf8ness) PerlIO_printf(Perl_debug_log, "; utf8ness=%d",
+                                                         *utf8ness);
+             PerlIO_printf(Perl_debug_log, "\n");
+            );
+
+    return retval;
+}
+
 /*
  * Initialize locale awareness.
  */

proto.h

@@ -2202,6 +2202,11 @@ PERL_CALLCONV char *	Perl_my_strftime(pTHX_ const char *fmt, int sec, int min, i
 #define PERL_ARGS_ASSERT_MY_STRFTIME	\
 	assert(fmt)
 
+PERL_CALLCONV char *	Perl_my_strftime8(pTHX_ const char *fmt, int sec, int min, int hour, int mday, int mon, int year, int wday, int yday, int isdst, int * utf8ness)
+			__attribute__format__(__strftime__,pTHX_1,0);
+#define PERL_ARGS_ASSERT_MY_STRFTIME8	\
+	assert(fmt)
+
 PERL_CALLCONV NV	Perl_my_strtod(const char * const s, char ** e)
 			__attribute__warn_unused_result__;
 #define PERL_ARGS_ASSERT_MY_STRTOD	\