ftruncate: Un-deprecate, concentrate on Win32 support.

* modules/ftruncate (Status, Notice): Remove sections.
(Depends-on): Add largefile.
* m4/ftruncate.m4 (gl_FUNC_FTRUNCATE): Drop failure message on
non-mingw platforms.
* lib/ftruncate.c: Remove code for the older platforms. For Win32,
include <io.h>.
* modules/perror-tests (Depends-on): Add ftruncate.
* doc/posix-functions/ftruncate.texi: Mention the MSVC problem and the
'ftruncate' module.

1 files changed, 4 insertions, 75 deletions

diff --git a/lib/ftruncate.c b/lib/ftruncate.c
index 33b69d8107..d5a3be144c 100644
--- a/lib/ftruncate.c
+++ b/lib/ftruncate.c
@@ -1,4 +1,4 @@
-/* ftruncate emulations that work on some System V's.
+/* ftruncate emulations for native Windows.
    This file is in the public domain.  */
 
 #include <config.h>
@@ -6,67 +6,9 @@
 /* Specification.  */
 #include <unistd.h>
 
-#include <sys/types.h>
-#include <fcntl.h>
+#if HAVE_CHSIZE
 
-#ifdef F_CHSIZE
-
-int
-ftruncate (int fd, off_t length)
-{
-  return fcntl (fd, F_CHSIZE, length);
-}
-
-#else /* not F_CHSIZE */
-# ifdef F_FREESP
-
-/* By William Kucharski <kucharsk@netcom.com>.  */
-
-#  include <sys/stat.h>
-#  include <errno.h>
-
-int
-ftruncate (int fd, off_t length)
-{
-  struct flock fl;
-  struct stat filebuf;
-
-  if (fstat (fd, &filebuf) < 0)
-    return -1;
-
-  if (filebuf.st_size < length)
-    {
-      /* Extend file length. */
-      if (lseek (fd, (length - 1), SEEK_SET) < 0)
-        return -1;
-
-      /* Write a "0" byte. */
-      if (write (fd, "", 1) != 1)
-        return -1;
-    }
-  else
-    {
-
-      /* Truncate length. */
-
-      fl.l_whence = 0;
-      fl.l_len = 0;
-      fl.l_start = length;
-      fl.l_type = F_WRLCK;      /* write lock on file space */
-
-      /* This relies on the *undocumented* F_FREESP argument to fcntl,
-         which truncates the file so that it ends at the position
-         indicated by fl.l_start.  Will minor miracles never cease?  */
-
-      if (fcntl (fd, F_FREESP, &fl) < 0)
-        return -1;
-    }
-
-  return 0;
-}
-
-# else /* not F_CHSIZE nor F_FREESP */
-#  if HAVE_CHSIZE                      /* native Windows, e.g. mingw */
+# include <io.h>
 
 int
 ftruncate (int fd, off_t length)
@@ -74,17 +16,4 @@ ftruncate (int fd, off_t length)
   return chsize (fd, length);
 }
 
-#  else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */
-
-#   include <errno.h>
-
-int
-ftruncate (int fd, off_t length)
-{
-  errno = EIO;
-  return -1;
-}
-
-#  endif /* not HAVE_CHSIZE */
-# endif /* not F_FREESP */
-#endif /* not F_CHSIZE */
+#endif