1 files changed, 90 insertions, 0 deletions
diff --git a/tests/test-mbsnlen.c b/tests/test-mbsnlen.c
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+++ b/tests/test-mbsnlen.c
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+/* Test of searching a string for a character outside a given set of characters.
+   Copyright (C) 2007-2024 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 <string.h>
+
+#include <locale.h>
+
+#include "macros.h"
+
+/* The mcel-based implementation of mbsnlen behaves differently than the
+   original one.  Namely, for invalid/incomplete byte sequences:
+   Where we ideally should have multi-byte-per-encoding-error (MEE) behaviour
+   everywhere, mcel implements single-byte-per-encoding-error (SEE) behaviour.
+   See <https://lists.gnu.org/archive/html/bug-gnulib/2023-07/msg00131.html>,
+       <https://lists.gnu.org/archive/html/bug-gnulib/2023-07/msg00145.html>.
+   Therefore, here we have different expected results, depending on the
+   implementation.  */
+#if GNULIB_MCEL_PREFER
+# define OR(a,b) b
+#else
+# define OR(a,b) a
+#endif
+
+int
+main ()
+{
+  /* configure should already have checked that the locale is supported.  */
+  if (setlocale (LC_ALL, "") == NULL)
+    return 1;
+
+  ASSERT (mbsnlen ("", 0) == 0);
+  ASSERT (mbsnlen ("", 1) == 1);
+  ASSERT (mbsnlen ("\0", 2) == 2);
+
+  ASSERT (mbsnlen ("H", 0) == 0);
+  ASSERT (mbsnlen ("H", 1) == 1);
+  ASSERT (mbsnlen ("H", 2) == 2);
+
+  ASSERT (mbsnlen ("Hello", 0) == 0);
+  ASSERT (mbsnlen ("Hello", 1) == 1);
+  ASSERT (mbsnlen ("Hello", 2) == 2);
+  ASSERT (mbsnlen ("Hello", 5) == 5);
+  ASSERT (mbsnlen ("Hello", 6) == 6);
+
+  /* The following tests shows how mbsnlen() is different from strnlen().  */
+  /* "äö" */
+  ASSERT (mbsnlen ("\303\244\303\266", 0) == 0);
+  ASSERT (mbsnlen ("\303\244\303\266", 1) == 1); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\303\244\303\266", 2) == 1);
+  ASSERT (mbsnlen ("\303\244\303\266", 3) == 2); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\303\244\303\266", 4) == 2);
+  ASSERT (mbsnlen ("\303\244\303\266", 5) == 3);
+  /* "7€" */
+  ASSERT (mbsnlen ("7\342\202\254", 0) == 0);
+  ASSERT (mbsnlen ("7\342\202\254", 1) == 1);
+  ASSERT (mbsnlen ("7\342\202\254", 2) == 2); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("7\342\202\254", 3) == OR(2,3)); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("7\342\202\254", 4) == 2);
+  ASSERT (mbsnlen ("7\342\202\254", 5) == 3);
+  /* "🐃" */
+  ASSERT (mbsnlen ("\360\237\220\203", 0) == 0);
+  ASSERT (mbsnlen ("\360\237\220\203", 1) == 1); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\360\237\220\203", 2) == OR(1,2)); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\360\237\220\203", 3) == OR(1,3)); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\360\237\220\203", 4) == 1);
+  ASSERT (mbsnlen ("\360\237\220\203", 5) == 2);
+
+  ASSERT (mbsnlen ("\303", 1) == 1); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\342\202", 2) == OR(1,2)); /* invalid multibyte sequence */
+  ASSERT (mbsnlen ("\360\237\220", 3) == OR(1,3)); /* invalid multibyte sequence */
+
+  return test_exit_status;
+}