2 files changed, 181 insertions, 0 deletions
diff --git a/gnulib b/gnulib
deleted file mode 160000
-Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1
diff --git a/gnulib/lib/fwriteerror.c b/gnulib/lib/fwriteerror.c
new file mode 100644
index 0000000..6b3a070
--- /dev/null
+++ b/gnulib/lib/fwriteerror.c
@@ -0,0 +1,181 @@
+/* Detect write error on a stream.
+   Copyright (C) 2003-2006, 2008-2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "fwriteerror.h"
+
+#include <errno.h>
+#include <stdbool.h>
+
+static int
+do_fwriteerror (FILE *fp, bool ignore_ebadf)
+{
+  /* State to allow multiple calls to fwriteerror (stdout).  */
+  static bool stdout_closed = false;
+
+  if (fp == stdout)
+    {
+      if (stdout_closed)
+        return 0;
+
+      /* If we are closing stdout, don't attempt to do it later again.  */
+      stdout_closed = true;
+    }
+
+  /* This function returns an error indication if there was a previous failure
+     or if fclose failed, with two exceptions:
+       - Ignore an fclose failure if there was no previous error, no data
+         remains to be flushed, and fclose failed with EBADF.  That can
+         happen when a program like cp is invoked like this `cp a b >&-'
+         (i.e., with standard output closed) and doesn't generate any
+         output (hence no previous error and nothing to be flushed).
+       - Ignore an fclose failure due to EPIPE.  That can happen when a
+         program blocks or ignores SIGPIPE, and the output pipe or socket
+         has no readers now.  The EPIPE tells us that we should stop writing
+         to this output.  That's what we are doing anyway here.
+
+     Need to
+     1. test the error indicator of the stream,
+     2. flush the buffers both in userland and in the kernel, through fclose,
+        testing for error again.  */
+
+  /* Clear errno, so that on non-POSIX systems the caller doesn't see a
+     wrong value of errno when we return -1.  */
+  errno = 0;
+
+  if (ferror (fp))
+    {
+      if (fflush (fp))
+        goto close_preserving_errno; /* errno is set here */
+      /* The stream had an error earlier, but its errno was lost.  If the
+         error was not temporary, we can get the same errno by writing and
+         flushing one more byte.  We can do so because at this point the
+         stream's contents is garbage anyway.  */
+      if (fputc ('\0', fp) == EOF)
+        goto close_preserving_errno; /* errno is set here */
+      if (fflush (fp))
+        goto close_preserving_errno; /* errno is set here */
+      /* Give up on errno.  */
+      errno = 0;
+      goto close_preserving_errno;
+    }
+
+  if (ignore_ebadf)
+    {
+      /* We need an explicit fflush to tell whether some output was already
+         done on FP.  */
+      if (fflush (fp))
+        goto close_preserving_errno; /* errno is set here */
+      if (fclose (fp) && errno != EBADF)
+        goto got_errno; /* errno is set here */
+    }
+  else
+    {
+      if (fclose (fp))
+        goto got_errno; /* errno is set here */
+    }
+
+  return 0;
+
+ close_preserving_errno:
+  /* There's an error.  Nevertheless call fclose(fp), for consistency
+     with the other cases.  */
+  {
+    int saved_errno = errno;
+    fclose (fp);
+    errno = saved_errno;
+  }
+ got_errno:
+  /* There's an error.  Ignore EPIPE.  */
+  if (errno == EPIPE)
+    return 0;
+  else
+    return -1;
+}
+
+int
+fwriteerror (FILE *fp)
+{
+  return do_fwriteerror (fp, false);
+}
+
+int
+fwriteerror_no_ebadf (FILE *fp)
+{
+  return do_fwriteerror (fp, true);
+}
+
+
+#if TEST
+
+/* Name of a file on which writing fails.  On systems without /dev/full,
+   you can choose a filename on a full file system.  */
+#define UNWRITABLE_FILE "/dev/full"
+
+int
+main ()
+{
+  static int sizes[] =
+    {
+       511,  512,  513,
+      1023, 1024, 1025,
+      2047, 2048, 2049,
+      4095, 4096, 4097,
+      8191, 8192, 8193
+    };
+  static char dummy[8193];
+  unsigned int i, j;
+
+  for (i = 0; i < sizeof (sizes) / sizeof (sizes[0]); i++)
+    {
+      size_t size = sizes[i];
+
+      for (j = 0; j < 2; j++)
+        {
+          /* Run a test depending on i and j:
+             Write size bytes and then calls fflush if j==1.  */
+          FILE *stream = fopen (UNWRITABLE_FILE, "w");
+
+          if (stream == NULL)
+            {
+              fprintf (stderr, "Test %u:%u: could not open file\n", i, j);
+              continue;
+            }
+
+          fwrite (dummy, 347, 1, stream);
+          fwrite (dummy, size - 347, 1, stream);
+          if (j)
+            fflush (stream);
+
+          if (fwriteerror (stream) == -1)
+            {
+              if (errno != ENOSPC)
+                fprintf (stderr, "Test %u:%u: fwriteerror ok, errno = %d\n",
+                         i, j, errno);
+            }
+          else
+            fprintf (stderr, "Test %u:%u: fwriteerror found no error!\n",
+                     i, j);
+        }
+    }
+
+  return 0;
+}
+
+#endif