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 bd1c4cb8726..48ff56a6099 100755
--- a/configure
+++ b/configure
@@ -18942,7 +18942,8 @@ fi
 
 
 
-for ac_func in cbrt dlopen fcvt fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink scandir setproctitle setsid sigprocmask symlink sysconf towlower utime utimes waitpid wcstombs wcstombs_l
+
+for ac_func in cbrt dlopen fcvt fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink scandir setproctitle setsid sigprocmask symlink sysconf 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 696533e99fc..a4ebd3f9dc7 100644
--- a/configure.in
+++ b/configure.in
@@ -1193,7 +1193,7 @@ PGAC_VAR_INT_TIMEZONE
 AC_FUNC_ACCEPT_ARGTYPES
 PGAC_FUNC_GETTIMEOFDAY_1ARG
 
-AC_CHECK_FUNCS([cbrt dlopen fcvt fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink scandir setproctitle setsid sigprocmask symlink sysconf towlower utime utimes waitpid wcstombs wcstombs_l])
+AC_CHECK_FUNCS([cbrt dlopen fcvt fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink scandir setproctitle setsid sigprocmask symlink sysconf 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 401440afae6..c3181be0d2f 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1191,17 +1191,17 @@ 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 7cda05c61ec..f901f82676b 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -339,6 +339,9 @@
 /* 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 a71d59a0fbd..9ad2c7780fb 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