- [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
-#include <fcntl.h>
-#include <errno.h>
-]], [[int result = 0;
- if (fcntl (0, F_DUPFD, -1) != -1) result |= 1;
- if (errno != EINVAL) result |= 2;
- return result;
- ]])],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <errno.h>
+ #include <fcntl.h>
+ #include <limits.h>
+ #include <sys/resource.h>
+ #include <unistd.h>
+ #ifndef RLIM_SAVED_CUR
+ # define RLIM_SAVED_CUR RLIM_INFINITY
+ #endif
+ #ifndef RLIM_SAVED_MAX
+ # define RLIM_SAVED_MAX RLIM_INFINITY
+ #endif
+ ]],
+ [[int result = 0;
+ int bad_fd = INT_MAX;
+ struct rlimit rlim;
+ if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
+ && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX
+ && rlim.rlim_cur != RLIM_INFINITY
+ && rlim.rlim_cur != RLIM_SAVED_MAX
+ && rlim.rlim_cur != RLIM_SAVED_CUR)
+ bad_fd = rlim.rlim_cur;
+ if (fcntl (0, F_DUPFD, -1) != -1) result |= 1;
+ if (errno != EINVAL) result |= 2;
+ if (fcntl (0, F_DUPFD, bad_fd) != -1) result |= 4;
+ if (errno != EINVAL) result |= 8;
+ return result;]])],