localeconv: Work around a mingw bug.

* m4/localeconv.m4 (gl_FUNC_LOCALECONV): Test whether fields of type
'char' are filled correctly.
(gl_PREREQ_LOCALECONV): Test whether 'struct lconv' has the int_{p,n}_*
members.
* lib/localeconv.c (FIX_CHAR_VALUE): New macro.
(localeconv): Replace negative field values with CHAR_MAX.
* doc/posix-functions/localeconv.texi: Mention the mingw bug.

1 files changed, 28 insertions, 17 deletions

diff --git a/lib/localeconv.c b/lib/localeconv.c
index 60c050f486..c1a34baa05 100644
--- a/lib/localeconv.c
+++ b/lib/localeconv.c
@@ -19,10 +19,14 @@
 /* Specification.  */
 #include <locale.h>
 
+#include <limits.h>
+
 #if HAVE_STRUCT_LCONV_DECIMAL_POINT
 
+# define FIX_CHAR_VALUE(x) ((x) >= 0 ? (x) : CHAR_MAX)
+
 /* Override for platforms where 'struct lconv' lacks the int_p_*, int_n_*
-   members.  */
+   members or where fields of type 'char' are set to -1 instead of CHAR_MAX.  */
 
 struct lconv *
 localeconv (void)
@@ -41,21 +45,30 @@ localeconv (void)
   result.positive_sign = sys_result->positive_sign;
   result.negative_sign = sys_result->negative_sign;
   result.currency_symbol = sys_result->currency_symbol;
-  result.frac_digits = sys_result->frac_digits;
-  result.p_cs_precedes = sys_result->p_cs_precedes;
-  result.p_sign_posn = sys_result->p_sign_posn;
-  result.p_sep_by_space = sys_result->p_sep_by_space;
-  result.n_cs_precedes = sys_result->n_cs_precedes;
-  result.n_sign_posn = sys_result->n_sign_posn;
-  result.n_sep_by_space = sys_result->n_sep_by_space;
+  result.frac_digits = FIX_CHAR_VALUE (sys_result->frac_digits);
+  result.p_cs_precedes = FIX_CHAR_VALUE (sys_result->p_cs_precedes);
+  result.p_sign_posn = FIX_CHAR_VALUE (sys_result->p_sign_posn);
+  result.p_sep_by_space = FIX_CHAR_VALUE (sys_result->p_sep_by_space);
+  result.n_cs_precedes = FIX_CHAR_VALUE (sys_result->n_cs_precedes);
+  result.n_sign_posn = FIX_CHAR_VALUE (sys_result->n_sign_posn);
+  result.n_sep_by_space = FIX_CHAR_VALUE (sys_result->n_sep_by_space);
   result.int_curr_symbol = sys_result->int_curr_symbol;
-  result.int_frac_digits = sys_result->int_frac_digits;
-  result.int_p_cs_precedes = sys_result->p_cs_precedes;
-  result.int_p_sign_posn = sys_result->p_sign_posn;
-  result.int_p_sep_by_space = sys_result->p_sep_by_space;
-  result.int_n_cs_precedes = sys_result->n_cs_precedes;
-  result.int_n_sign_posn = sys_result->n_sign_posn;
-  result.int_n_sep_by_space = sys_result->n_sep_by_space;
+  result.int_frac_digits = FIX_CHAR_VALUE (sys_result->int_frac_digits);
+# if HAVE_STRUCT_LCONV_INT_P_CS_PRECEDES
+  result.int_p_cs_precedes = FIX_CHAR_VALUE (sys_result->int_p_cs_precedes);
+  result.int_p_sign_posn = FIX_CHAR_VALUE (sys_result->int_p_sign_posn);
+  result.int_p_sep_by_space = FIX_CHAR_VALUE (sys_result->int_p_sep_by_space);
+  result.int_n_cs_precedes = FIX_CHAR_VALUE (sys_result->int_n_cs_precedes);
+  result.int_n_sign_posn = FIX_CHAR_VALUE (sys_result->int_n_sign_posn);
+  result.int_n_sep_by_space = FIX_CHAR_VALUE (sys_result->int_n_sep_by_space);
+# else
+  result.int_p_cs_precedes = FIX_CHAR_VALUE (sys_result->p_cs_precedes);
+  result.int_p_sign_posn = FIX_CHAR_VALUE (sys_result->p_sign_posn);
+  result.int_p_sep_by_space = FIX_CHAR_VALUE (sys_result->p_sep_by_space);
+  result.int_n_cs_precedes = FIX_CHAR_VALUE (sys_result->n_cs_precedes);
+  result.int_n_sign_posn = FIX_CHAR_VALUE (sys_result->n_sign_posn);
+  result.int_n_sep_by_space = FIX_CHAR_VALUE (sys_result->n_sep_by_space);
+# endif
 
   return &result;
 }
@@ -64,8 +77,6 @@ localeconv (void)
 
 /* Override for platforms where 'struct lconv' is a dummy.  */
 
-# include <limits.h>
-
 struct lconv *
 localeconv (void)
 {