Make configure probe for mbstowcs_l as well as wcstombs_l.

We previously supposed that any given platform would supply both or neither
of these functions, so that one configure test would be sufficient.  It now
appears that at least on AIX this is not the case ... which is likely an
AIX bug, but nonetheless we need to cope with it.  So use separate tests.
Per bug #6758; thanks to Andrew Hastie for doing the followup testing
needed to confirm what was happening.

Backpatch to 9.1, where we began using these functions.

5 files changed, 12 insertions, 5 deletions

diff --git a/configure b/configure
index 58c4ac426f3..704142ebb50 100755
--- a/configure
+++ b/configure
@@ -19149,7 +19149,8 @@ fi
 
 
 
-for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l
+
+for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l
 do
 as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
diff --git a/configure.in b/configure.in
index c6a0a5ce6b4..e61e65f4e8b 100644
--- a/configure.in
+++ b/configure.in
@@ -1197,7 +1197,7 @@ PGAC_VAR_INT_TIMEZONE
 AC_FUNC_ACCEPT_ARGTYPES
 PGAC_FUNC_GETTIMEOFDAY_1ARG
 
-AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l])
+AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l])
 
 AC_REPLACE_FUNCS(fseeko)
 case $host_os in
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index de881bf6344..495fe4db6ae 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1205,17 +1205,17 @@ char2wchar(wchar_t *to, size_t tolen, const char *from, size_t fromlen,
 		else
 		{
 #ifdef HAVE_LOCALE_T
-#ifdef HAVE_WCSTOMBS_L
+#ifdef HAVE_MBSTOWCS_L
 			/* Use mbstowcs_l for nondefault locales */
 			result = mbstowcs_l(to, str, tolen, locale);
-#else							/* !HAVE_WCSTOMBS_L */
+#else							/* !HAVE_MBSTOWCS_L */
 			/* We have to temporarily set the locale as current ... ugh */
 			locale_t	save_locale = uselocale(locale);
 
 			result = mbstowcs(to, str, tolen);
 
 			uselocale(save_locale);
-#endif   /* HAVE_WCSTOMBS_L */
+#endif   /* HAVE_MBSTOWCS_L */
 #else							/* !HAVE_LOCALE_T */
 			/* Can't have locale != 0 without HAVE_LOCALE_T */
 			elog(ERROR, "mbstowcs_l is not available");
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 8430608bfc8..b469d52718d 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -333,6 +333,9 @@
 /* Define to 1 if `long long int' works and is 64 bits. */
 #undef HAVE_LONG_LONG_INT_64
 
+/* Define to 1 if you have the `mbstowcs_l' function. */
+#undef HAVE_MBSTOWCS_L
+
 /* Define to 1 if you have the `memmove' function. */
 #undef HAVE_MEMMOVE
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 52b13f3217c..cf92bda0730 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -249,6 +249,9 @@
 #define HAVE_LONG_LONG_INT_64
 #endif
 
+/* Define to 1 if you have the `mbstowcs_l' function. */
+#define HAVE_MBSTOWCS_L 1
+
 /* Define to 1 if you have the `memmove' function. */
 #define HAVE_MEMMOVE 1