dup, dup2, fcntl: support a directory fd on OS/2 kLIBC

On OS/2 kLIBC, dup(), dup2() and fcntl() do not work on a directory
fd.

* lib/dup.c (dup_nothrow): New.
* lib/dup2.c (klibc_dup2dirfd): New. dup2() for a directory fd.
(klibc_dup2): New.
* lib/fcntl.c (klibc_fcntl): New.
* m4/dup.m4 (gl_FUNC_DUP): Check if dup() works on a directory fd.
* m4/dup2.m4 (gl_FUNC_DUP2): Check if dup2() works on a directory fd.
* m4/fcntl.m4 (gl_FUNC_FCNTL): Check if F_DUPFD works on a directory
fd.

1 files changed, 51 insertions, 0 deletions

diff --git a/lib/dup2.c b/lib/dup2.c
index c913f473ad..5d026f21fa 100644
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -85,6 +85,57 @@ ms_windows_dup2 (int fd, int desired_fd)
 
 #  define dup2 ms_windows_dup2
 
+# elif defined __KLIBC__
+
+#  include <InnoTekLIBC/backend.h>
+
+static int
+klibc_dup2dirfd (int fd, int desired_fd)
+{
+  int tempfd;
+  int dupfd;
+
+  tempfd = open ("NUL", O_RDONLY);
+  if (tempfd == -1)
+    return -1;
+
+  if (tempfd == desired_fd)
+    {
+      close (tempfd);
+
+      char path[_MAX_PATH];
+      if (__libc_Back_ioFHToPath (fd, path, sizeof (path)))
+        return -1;
+
+      return open(path, O_RDONLY);
+    }
+
+  dupfd = klibc_dup2dirfd (fd, desired_fd);
+
+  close (tempfd);
+
+  return dupfd;
+}
+
+static int
+klibc_dup2 (int fd, int desired_fd)
+{
+  int dupfd;
+  struct stat sbuf;
+
+  dupfd = dup2 (fd, desired_fd);
+  if (dupfd == -1 && errno == ENOTSUP \
+      && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode))
+    {
+      close (desired_fd);
+
+      return klibc_dup2dirfd (fd, desired_fd);
+    }
+
+  return dupfd;
+}
+
+#  define dup2 klibc_dup2
 # endif
 
 int