1 files changed, 77 insertions, 0 deletions
diff --git a/gnulib-tests/test-freadahead.c b/gnulib-tests/test-freadahead.c
new file mode 100644
index 0000000..33adf1a
--- /dev/null
+++ b/gnulib-tests/test-freadahead.c
@@ -0,0 +1,77 @@
+/* Test of freadahead() function.
+   Copyright (C) 2007-2023 Free Software Foundation, Inc.
+
+   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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
+
+#include <config.h>
+
+#include "freadahead.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "macros.h"
+
+int
+main (int argc, char **argv)
+{
+  int nbytes = atoi (argv[1]);
+  if (nbytes > 0)
+    {
+      void *buf = malloc (nbytes);
+      ASSERT (fread (buf, 1, nbytes, stdin) == nbytes);
+      free (buf);
+    }
+
+  if (nbytes == 0)
+    ASSERT (freadahead (stdin) == 0);
+  else
+    {
+      if (lseek (0, 0, SEEK_CUR) == nbytes)
+        /* An unbuffered stdio, such as BeOS or on uClibc compiled without
+           __STDIO_BUFFERS.  */
+        ASSERT (freadahead (stdin) == 0);
+      else
+        {
+          /* Normal buffered stdio.  */
+          size_t buffered;
+          int c, c2;
+
+          ASSERT (freadahead (stdin) != 0);
+          buffered = freadahead (stdin);
+
+          c = fgetc (stdin);
+          ASSERT (freadahead (stdin) == buffered - 1);
+          ungetc (c, stdin);
+          ASSERT (freadahead (stdin) == buffered);
+          c2 = fgetc (stdin);
+          ASSERT (c2 == c);
+          ASSERT (freadahead (stdin) == buffered - 1);
+
+          c = '@';
+          ungetc (c, stdin);
+          ASSERT (freadahead (stdin) == buffered);
+          c2 = fgetc (stdin);
+          ASSERT (c2 == c);
+          ASSERT (freadahead (stdin) == buffered - 1);
+        }
+    }
+
+  /* Free memory allocated during ungetc().  */
+  fclose (stdin);
+
+  return 0;
+}