According to Unicode spec. v3.0 (see 5.15) and comment to #61560 text like
"One.Two" is two sentences, not one. But the specified functions work wrong
in this case.


Test case:

main (int argc, char** argv)
{
    gtk_init (&argc, &argv);

    test ("One.Two", 4);
    test ("One.two", 4);
    test ("One!Two", 4);
    test ("One?Two", 4);
    test ("One?!Two", 5);
}

void 
test (gchar* str, int pos)
{
    GtkTextIter iter;
    GtkTextBuffer* buffer;
    gboolean returns;

    buffer = gtk_text_buffer_new (NULL);

    gtk_text_buffer_set_text (buffer, str, strlen (str));
    gtk_text_buffer_get_iter_at_offset(buffer, &iter, pos);

    returns = gtk_text_iter_starts_sentence (&iter);

    printf ("returns = %d\n", returns);
}

Output:
returns = 0
returns = 0
returns = 1
returns = 1
returns = 1

I assume that gtk_text_iter_starts_sentence() should return TRUE in the
first case. All other cases are handled correctly.

Same for gtk_text_iter_ends_sentence().