check if strptime() works correctly and disable its use if it doesn't [backport from HEAD]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@46461 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

configure.in

@@ -6085,8 +6085,7 @@ dnl ---------------------------------------------------------------------------
 
 if test "$wxUSE_DATETIME" = "yes"; then
     dnl check for strptime and for its declaration as some systems lack it
-    dnl FIXME: use WX_CHECK_FUNCS instead
-    AC_CHECK_FUNCS(strptime)
+    AC_CHECK_FUNC(strptime)
     if test "$ac_cv_func_strptime" = "yes"; then
         AC_CACHE_CHECK([for strptime declaration], wx_cv_func_strptime_decl,
             [
@@ -6108,6 +6107,39 @@ if test "$wxUSE_DATETIME" = "yes"; then
     fi
     if test "$wx_cv_func_strptime_decl" = "yes"; then
         AC_DEFINE(HAVE_STRPTIME_DECL)
+    else
+        wx_strptime_decl="extern char *strptime(const char *, const char *, struct tm *);"
+    fi
+    if test "$ac_cv_func_strptime" = "yes"; then
+        dnl strptime() behaviour doesn't conform to POSIX under Mac OS X <
+        dnl 10.5 and possibly other BSD variants, check that strptime() we
+        dnl have fails to parse format when the string doesn't match it instea
+        dnl of just stopping immediately and returning non-NULL
+        AC_CACHE_CHECK([whether strptime() fails on invalid strings],
+            wx_cv_func_strptime_ok,
+            [AC_RUN_IFELSE(
+                [
+                    #include <stdlib.h>
+                    #include <time.h>
+                    #include "confdefs.h"
+
+                    $wx_strptime_decl
+
+                    int main()
+                    {
+                        return !!strptime("", "%x", NULL);
+                    }
+                ],
+                wx_cv_func_strptime_ok=yes,
+                wx_cv_func_strptime_ok=no,
+                dnl be pessimistic when cross-compiling
+                wx_cv_func_strptime_ok=no
+            )]
+        )
+
+        if test "$wx_cv_func_strptime_ok" = "yes"; then
+            AC_DEFINE(HAVE_STRPTIME)
+        fi
     fi
 
     dnl check for timezone variable