1 files changed, 97 insertions, 0 deletions
diff --git a/libio/tst-bz22415.c b/libio/tst-bz22415.c
new file mode 100644
index 0000000000..d7b23fefb8
--- /dev/null
+++ b/libio/tst-bz22415.c
@@ -0,0 +1,97 @@
+/* Check static buffer handling with setvbuf (BZ #22415)
+
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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.
+
+   The GNU C Library 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 the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include <mcheck.h>
+
+#include <support/check.h>
+#include <support/temp_file.h>
+
+static int
+do_test (void)
+{
+  mtrace ();
+
+  char *temp_file;
+  TEST_VERIFY_EXIT (create_temp_file ("tst-bz22145.", &temp_file));
+
+  char buf[BUFSIZ];
+
+  {
+    /* Check if backup buffer is correctly freed and changing back
+       to normal buffer does not trigger an invalid free in case of
+       static buffer set by setvbuf.  */
+
+    FILE *f = fopen (temp_file, "w+b");
+    TEST_VERIFY_EXIT (f != NULL);
+
+    TEST_VERIFY_EXIT (setvbuf (f, buf, _IOFBF, BUFSIZ) == 0);
+    TEST_VERIFY_EXIT (ungetc ('x', f) == 'x');
+    TEST_VERIFY_EXIT (fseek (f, 0L, SEEK_SET) == 0);
+    TEST_VERIFY_EXIT (fputc ('y', f) ==  'y');
+
+    TEST_VERIFY_EXIT (fclose (f) == 0);
+  }
+
+  {
+    /* Check if backup buffer is correctly freed and changing back
+       to normal buffer does not trigger an invalid free in case of
+       static buffer set by setvbuf.  */
+
+    FILE *f = fopen (temp_file, "w+b");
+    TEST_VERIFY_EXIT (f != NULL);
+
+    TEST_VERIFY_EXIT (setvbuf (f, buf, _IOFBF, BUFSIZ) == 0);
+    TEST_VERIFY_EXIT (ungetc ('x', f) == 'x');
+    TEST_VERIFY_EXIT (fputc ('y', f) ==  'y');
+
+    TEST_VERIFY_EXIT (fclose (f) == 0);
+  }
+
+  {
+    FILE *f = fopen (temp_file, "w+b");
+    TEST_VERIFY_EXIT (f != NULL);
+
+    TEST_VERIFY_EXIT (setvbuf (f, buf, _IOFBF, BUFSIZ) == 0);
+    TEST_VERIFY_EXIT (ungetwc (L'x', f) == L'x');
+    TEST_VERIFY_EXIT (fseek (f, 0L, SEEK_SET) == 0);
+    TEST_VERIFY_EXIT (fputwc (L'y', f) ==  L'y');
+
+    TEST_VERIFY_EXIT (fclose (f) == 0);
+  }
+
+  {
+    FILE *f = fopen (temp_file, "w+b");
+    TEST_VERIFY_EXIT (f != NULL);
+
+    TEST_VERIFY_EXIT (setvbuf (f, buf, _IOFBF, BUFSIZ) == 0);
+    TEST_VERIFY_EXIT (ungetwc (L'x', f) == L'x');
+    TEST_VERIFY_EXIT (fputwc (L'y', f) ==  L'y');
+
+    TEST_VERIFY_EXIT (fclose (f) == 0);
+  }
+
+  free (temp_file);
+
+  return 0;
+}
+
+#include <support/test-driver.c>