Move code from POSIX.xs to locale.c

This avoids duplicated logic.

embed.fnc

@@ -1598,6 +1598,7 @@ ATdo	|const char*|Perl_langinfo|const nl_item item
 #else
 ATdo	|const char*|Perl_langinfo|const int item
 #endif
+pEX	|int	|mbtowc_|NULLOK const wchar_t * pwc|NULLOK const char * s|const Size_t len
 CpO	|int	|init_i18nl10n	|int printwarn
 CbpOD	|int	|init_i18nl14n	|int printwarn
 p	|char*	|my_strerror	|const int errnum

embed.h

@@ -952,6 +952,7 @@
 #define get_prop_values		Perl_get_prop_values
 #define grok_atoUV		Perl_grok_atoUV
 #define load_charnames(a,b,c,d)	Perl_load_charnames(aTHX_ a,b,c,d)
+#define mbtowc_(a,b,c)		Perl_mbtowc_(aTHX_ a,b,c)
 #define mg_find_mglob(a)	Perl_mg_find_mglob(aTHX_ a)
 #define multiconcat_stringify(a)	Perl_multiconcat_stringify(aTHX_ a)
 #define multideref_stringify(a,b)	Perl_multideref_stringify(aTHX_ a,b)

ext/POSIX/POSIX.xs

@@ -3397,30 +3397,18 @@ mblen(s, n = ~0)
     OUTPUT:
         RETVAL
 
-#if defined(HAS_MBRTOWC) && (defined(USE_ITHREADS) || ! defined(HAS_MBTOWC))
-#  define USE_MBRTOWC
-#else
-#  undef USE_MBRTOWC
-#endif
-
 int
 mbtowc(pwc, s, n = ~0)
 	SV *	        pwc
 	SV *		s
 	size_t		n
     CODE:
+        RETVAL = -1;
+#if defined(HAS_MBTOWC) || defined(HAS_MBRTOWC)
         errno = 0;
         SvGETMAGIC(s);
         if (! SvOK(s)) { /* Initialize state */
-#ifdef USE_MBRTOWC
-            /* Initialize the shift state to all zeros in PL_mbrtowc_ps. */
-            memzero(&PL_mbrtowc_ps, sizeof(PL_mbrtowc_ps));
-            RETVAL = 0;
-#else
-            MBTOWC_LOCK;
-            RETVAL = mbtowc(NULL, NULL, 0);
-            MBTOWC_UNLOCK;
-#endif
+            mbtowc_(NULL, NULL, 0);
         }
         else {  /* Not resetting state */
             wchar_t wc;
@@ -3433,15 +3421,7 @@ mbtowc(pwc, s, n = ~0)
                 size_t len;
                 char * string = SvPV(byte_s, len);
                 if (n < len) len = n;
-#ifdef USE_MBRTOWC
-                RETVAL = (SSize_t) mbrtowc(&wc, string, len, &PL_mbrtowc_ps);
-#else
-                /* Locking prevents races, but locales can be switched out
-                 * without locking, so this isn't a cure all */
-                MBTOWC_LOCK;
-                RETVAL = mbtowc(&wc, string, len);
-                MBTOWC_UNLOCK;
-#endif
+                RETVAL = mbtowc_(&wc, string, len);
                 if (RETVAL >= 0) {
                     sv_setiv_mg(pwc, wc);
                 }
@@ -3450,6 +3430,7 @@ mbtowc(pwc, s, n = ~0)
                 }
             }
         }
+#endif
     OUTPUT:
         RETVAL
 

locale.c

@@ -2622,6 +2622,69 @@ S_save_to_buffer(const char * string, const char **buf, Size_t *buf_size,
     return *buf;
 }
 
+int
+Perl_mbtowc_(pTHX_ const wchar_t * pwc, const char * s, const Size_t len)
+{
+
+#if ! defined(HAS_MBRTOWC) && ! defined(HAS_MBTOWC)
+
+    PERL_UNUSED_ARG(pwc);
+    PERL_UNUSED_ARG(s);
+    PERL_UNUSED_ARG(len);
+    return -1;
+
+#else   /* Below we have some form of mbtowc() */
+#   if defined(HAS_MBRTOWC)                                     \
+   && (defined(USE_LOCALE_THREADS) || ! defined(HAS_MBTOWC))
+#    define USE_MBRTOWC
+#  else
+#    undef USE_MBRTOWC
+#  endif
+
+    int retval = -1;
+
+    if (s == NULL) { /* Initialize the shift state to all zeros in
+                        PL_mbrtowc_ps. */
+
+#  if defined(USE_MBRTOWC)
+
+        memzero(&PL_mbrtowc_ps, sizeof(PL_mbrtowc_ps));
+        return 0;
+
+#  else
+
+        MBTOWC_LOCK;
+        SETERRNO(0, 0);
+        retval = mbtowc(NULL, NULL, 0);
+        MBTOWC_UNLOCK;
+        return retval;
+
+#  endif
+
+    }
+
+#  if defined(USE_MBRTOWC)
+
+    SETERRNO(0, 0);
+    retval = (SSize_t) mbrtowc((wchar_t *) pwc, s, len, &PL_mbrtowc_ps);
+
+#  else
+
+    /* Locking prevents races, but locales can be switched out without locking,
+     * so this isn't a cure all */
+    MBTOWC_LOCK;
+    SETERRNO(0, 0);
+    retval = mbtowc((wchar_t *) pwc, s, len);
+    MBTOWC_UNLOCK;
+
+#  endif
+
+    return retval;
+
+#endif
+
+}
+
 /*
 
 =for apidoc Perl_langinfo
@@ -4943,47 +5006,13 @@ Perl__is_cur_LC_category_utf8(pTHX_ int category)
       * late adder to C89, so very likely to have it.  However, testing has
       * shown that, like nl_langinfo() above, there are locales that are not
       * strictly UTF-8 that this will return that they are */
-
         {
             wchar_t wc;
             int len;
-            dSAVEDERRNO;
-
-#      if defined(HAS_MBRTOWC) && defined(USE_LOCALE_THREADS)
-
-            mbstate_t ps;
 
-#      endif
-
-            /* mbrtowc() and mbtowc() convert a byte string to a wide
-             * character.  Feed a byte string to one of them and check that the
-             * result is the expected Unicode code point */
-
-#      if defined(HAS_MBRTOWC) && defined(USE_LOCALE_THREADS)
-            /* Prefer this function if available, as it's reentrant */
-
-            memzero(&ps, sizeof(ps));;
-            PERL_UNUSED_RESULT(mbrtowc(&wc, NULL, 0, &ps)); /* Reset any shift
-                                                               state */
-            SETERRNO(0, 0);
-            len = mbrtowc(&wc, STR_WITH_LEN(REPLACEMENT_CHARACTER_UTF8), &ps);
-            SAVE_ERRNO;
-
-#      else
-
-            MBTOWC_LOCK;
-            PERL_UNUSED_RESULT(mbtowc(&wc, NULL, 0));/* Reset any shift state */
-            SETERRNO(0, 0);
-            len = mbtowc(&wc, STR_WITH_LEN(REPLACEMENT_CHARACTER_UTF8));
-            SAVE_ERRNO;
-            MBTOWC_UNLOCK;
-
-#      endif
-
-            RESTORE_ERRNO;
-            DEBUG_Lv(PerlIO_printf(Perl_debug_log,
-                    "\treturn from mbtowc; len=%d; code_point=%x; errno=%d\n",
-                                   len,      (unsigned int) wc, GET_ERRNO));
+            PERL_UNUSED_RESULT(mbtowc_(NULL, NULL, 0));
+            len = mbtowc_(&wc, REPLACEMENT_CHARACTER_UTF8,
+                       STRLENs(REPLACEMENT_CHARACTER_UTF8));
 
             is_utf8 = cBOOL(   len == STRLENs(REPLACEMENT_CHARACTER_UTF8)
                             && wc == (wchar_t) UNICODE_REPLACEMENT);

proto.h

@@ -2022,6 +2022,8 @@ PERL_CALLCONV Malloc_t	Perl_malloc(MEM_SIZE nbytes)
 
 PERL_CALLCONV I32 *	Perl_markstack_grow(pTHX);
 #define PERL_ARGS_ASSERT_MARKSTACK_GROW
+PERL_CALLCONV int	Perl_mbtowc_(pTHX_ const wchar_t * pwc, const char * s, const Size_t len);
+#define PERL_ARGS_ASSERT_MBTOWC_
 PERL_CALLCONV SV*	Perl_mess(pTHX_ const char* pat, ...)
 			__attribute__format__(__printf__,pTHX_1,pTHX_2);
 #define PERL_ARGS_ASSERT_MESS	\