S_parse_LC_ALL_string(): Add parameter

This tells the function to panic instead of returning failure upon
encountering an error.

embed.fnc

@@ -4393,6 +4393,7 @@ S	|void	|give_perl_locale_control				\
 S	|parse_LC_ALL_string_return|parse_LC_ALL_string 		\
 				|NN const char *string			\
 				|NN const char **output 		\
+				|const bool panic_on_error		\
 				|const line_t caller_line
 #   else
 S	|void	|give_perl_locale_control				\

embed.h

@@ -1295,7 +1295,7 @@
 #       endif
 #       if defined(LC_ALL)
 #         define give_perl_locale_control(a,b)  S_give_perl_locale_control(aTHX_ a,b)
-#         define parse_LC_ALL_string(a,b,c,d)   S_parse_LC_ALL_string(aTHX_ a,b,c,d)
+#         define parse_LC_ALL_string(a,b,c,d,e) S_parse_LC_ALL_string(aTHX_ a,b,c,d,e)
 #       else
 #         define give_perl_locale_control(a,b)  S_give_perl_locale_control(aTHX_ a,b)
 #       endif

locale.c

@@ -234,6 +234,7 @@ S_positional_name_value_xlation(const char * locale, bool direction)
     /* This parses either notation */
     switch (parse_LC_ALL_string(locale,
                                 (const char **) &individ_locales,
+                                false,      /* Don't panic on error */
                                 __LINE__))
     {
       case invalid:
@@ -1087,6 +1088,7 @@ Perl_locale_panic(const char * msg,
 STATIC parse_LC_ALL_string_return
 S_parse_LC_ALL_string(pTHX_ const char * string,
                             const char ** output,
+                            const bool panic_on_error,
                             const line_t caller_line)
 {
     /* This function parses the value of the input 'string' which is expected
@@ -1119,6 +1121,8 @@ S_parse_LC_ALL_string(pTHX_ const char * string,
      * syntactic errors, and if found, returns 'invalid'.  'output' will not be
      * filled in that case, but the input state of it isn't necessarily
      * preserved.  Turning on -DL debugging will give details as to the error.
+     * If 'panic_on_error' is 'true', the function panics instead of returning
+     * on error, with a message giving the details.
      *
      */
 
@@ -1322,6 +1326,10 @@ S_parse_LC_ALL_string(pTHX_ const char * string,
 
     DEBUG_L(PerlIO_printf(Perl_debug_log, "%s", msg));
 
+    if (panic_on_error) {
+        locale_panic_via_(msg, __FILE__, caller_line);
+    }
+
     return invalid;
 }
 
@@ -1414,6 +1422,7 @@ S_stdize_locale(pTHX_ const int category,
     else {
         switch (parse_LC_ALL_string(input_locale,
                                     (const char **) & individ_locales,
+                                    false,    /* Don't panic on error */
                                     caller_line))
         {
           case invalid:
@@ -1893,6 +1902,7 @@ S_bool_setlocale_2008_i(pTHX_
     if (index == LC_ALL_INDEX_) {
         switch (parse_LC_ALL_string(new_locale,
                                     (const char **) &new_locales,
+                                    false,    /* Don't panic on error */
                                     caller_line))
         {
           case invalid:
@@ -2557,6 +2567,7 @@ S_find_locale_from_environment(pTHX_ const unsigned int index)
          * component of it.  Split the result into its individual components */
         switch (parse_LC_ALL_string(lc_all,
                                     (const char **) &locale_names,
+                                    false,    /* Don't panic on error */
                                     __LINE__))
         {
           case invalid: