1 files changed, 84 insertions, 0 deletions

diff --git a/gl/fseterr.c b/gl/fseterr.c
new file mode 100644
index 00000000..a01ef2af
--- /dev/null
+++ b/gl/fseterr.c
@@ -0,0 +1,84 @@
+/* Set the error indicator of a stream.
+   Copyright (C) 2007-2025 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "fseterr.h"
+
+#include <errno.h>
+
+#include "stdio-impl.h"
+
+/* This file is not used on systems that have the __fseterr function,
+   namely OpenBSD >= 7.6, musl libc, Haiku >= hrev58760.  */
+
+void
+fseterr (FILE *fp)
+{
+  /* Most systems provide FILE as a struct and the necessary bitmask in
+     <stdio.h>, because they need it for implementing getc() and putc() as
+     fast macros.  */
+#if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
+  /* GNU libc, BeOS, Haiku, Linux libc5 */
+  fp->_flags |= _IO_ERR_SEEN;
+#elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
+  /* FreeBSD, NetBSD, OpenBSD < 7.6, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
+  fp_->_flags |= __SERR;
+#elif defined __EMX__               /* emx+gcc */
+  fp->_flags |= _IOERR;
+#elif defined __minix               /* Minix */
+  fp->_flags |= _IOERR;
+#elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
+  fp_->_flag |= _IOERR;
+#elif defined __UCLIBC__            /* uClibc */
+  fp->__modeflags |= __FLAG_ERROR;
+#elif defined __QNX__               /* QNX */
+  fp->_Mode |= 0x200 /* _MERR */;
+#elif defined __MINT__              /* Atari FreeMiNT */
+  fp->__error = 1;
+#elif defined EPLAN9                /* Plan9 */
+  if (fp->state != 0 /* CLOSED */)
+    fp->state = 5 /* ERR */;
+#elif 0                             /* unknown  */
+  /* Portable fallback, based on an idea by Rich Felker.
+     Wow! 6 system calls for something that is just a bit operation!
+     Not activated on any system, because there is no way to repair FP when
+     the sequence of system calls fails, and library code should not call
+     abort().  */
+  int saved_errno;
+  int fd;
+  int fd2;
+
+  saved_errno = errno;
+  fflush (fp);
+  fd = fileno (fp);
+  fd2 = dup (fd);
+  if (fd2 >= 0)
+    {
+      close (fd);
+      fputc ('\0', fp); /* This should set the error indicator.  */
+      fflush (fp);      /* Or this.  */
+      if (dup2 (fd2, fd) < 0)
+        /* Whee... we botched the stream and now cannot restore it!  */
+        abort ();
+      close (fd2);
+    }
+  errno = saved_errno;
+#else
+ #error "Please port gnulib fseterr.c to your platform! Look at the definitions of ferror and clearerr on your system, then report this to bug-gnulib."
+#endif
+}