Commit 3e89b19c authored by Philip Withnall's avatar Philip Withnall

gutf8: Fix documentation for g_utf8_get_char_validated() length limits

If g_utf8_get_char_validated() encounters a nul byte in the middle of a
string of given longer length, it returns -2, indicating a partial
gunichar. That is not the obvious behaviour, but since
g_utf8_get_char_validated() has been API for a long time, the behaviour
cannot be changed.

Document it, and add some unit tests (for this behaviour and the other
behaviour of g_utf8_get_char_validated()).
Signed-off-by: Philip Withnall's avatarPhilip Withnall <withnall@endlessm.com>

https://bugzilla.gnome.org/show_bug.cgi?id=780095
parent 428acd9b
......@@ -654,6 +654,10 @@ g_utf8_get_char_extended (const gchar *p,
* This function checks for incomplete characters, for invalid characters
* such as characters that are out of the range of Unicode, and for
* overlong encodings of valid characters.
*
* Note that g_utf8_get_char_validated() returns (gunichar)-2 if
* @max_len is positive and any of the bytes in the first UTF-8 character
* sequence are nul.
*
* Returns: the resulting character. If @p points to a partial
* sequence at the end of a string that could begin a valid
......
......@@ -292,6 +292,57 @@ do_test (gconstpointer d)
}
}
/* Test the behaviour of g_utf8_get_char_validated() with various inputs and
* length restrictions. */
static void
test_utf8_get_char_validated (void)
{
const struct {
const gchar *buf;
gssize max_len;
gunichar expected_result;
} test_vectors[] = {
/* Bug #780095: */
{ "\xC0\x00_45678", 8, (gunichar) -2 },
{ "\xC0\x00_45678", -1, (gunichar) -2 },
/* It seems odd that the return value differs with the length input, but
* that’s how it’s documented: */
{ "", 0, (gunichar) -2 },
{ "", -1, (gunichar) 0 },
/* Normal inputs: */
{ "hello", 5, (gunichar) 'h' },
{ "hello", -1, (gunichar) 'h' },
{ "\xD8\x9F", 2, 0x061F },
{ "\xD8\x9F", -1, 0x061F },
{ "\xD8\x9Fmore", 6, 0x061F },
{ "\xD8\x9Fmore", -1, 0x061F },
{ "\xE2\x96\xB3", 3, 0x25B3 },
{ "\xE2\x96\xB3", -1, 0x25B3 },
{ "\xE2\x96\xB3more", 7, 0x25B3 },
{ "\xE2\x96\xB3more", -1, 0x25B3 },
{ "\xF0\x9F\x92\xA9", 4, 0x1F4A9 },
{ "\xF0\x9F\x92\xA9", -1, 0x1F4A9 },
{ "\xF0\x9F\x92\xA9more", 8, 0x1F4A9 },
{ "\xF0\x9F\x92\xA9more", -1, 0x1F4A9 },
/* Partial unichars: */
{ "\xD8", -1, (gunichar) -2 },
{ "\xD8\x9F", 1, (gunichar) -2 },
{ "\xCE", -1, (gunichar) -2 },
{ "\xCE", 1, (gunichar) -2 },
};
gsize i;
for (i = 0; i < G_N_ELEMENTS (test_vectors); i++)
{
gunichar actual_result;
g_test_message ("Vector %" G_GSIZE_FORMAT, i);
actual_result = g_utf8_get_char_validated (test_vectors[i].buf,
test_vectors[i].max_len);
g_assert_cmpint (actual_result, ==, test_vectors[i].expected_result);
}
}
int
main (int argc, char *argv[])
{
......@@ -307,5 +358,7 @@ main (int argc, char *argv[])
g_free (path);
}
g_test_add_func ("/utf8/get-char-validated", test_utf8_get_char_validated);
return g_test_run ();
}
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