Hi Pádraig,
> I was testing multi-byte enhancements to coreutils/join with:
> LC_ALL=en_US.utf8 join -i <(env printf '1\x00\n') <(env printf '2\x00\n')
> and noticed it spun the CPU because of the NUL char.
> The attached fixes the issue for me. This function is supposed
> to skip over NUL chars like this right?
Right.
> --- a/lib/mbmemcasecoll.c 2010-01-04 01:10:30.000000000 +0000
> +++ b/lib/mbmemcasecoll.c 2010-09-21 23:52:23.000000000 +0000
> @@ -61,6 +63,8 @@
> break;
> if (n1 != (size_t)(-1))
> {
> + if (n1 == 0)
> + n1 = 1; /* copy NUL characters. */
> wint_t wc2 = towlower (wc1);
>
> if (wc2 != wc1)
The patch is right, except that we stick with C89 syntax in gnulib: no
statements before declarations. I'm adding the fix and a test case:
2010-09-22 Pádraig Brady <[email protected]>
Bruno Haible <[email protected]>
Fix endless loop in mbmemcasecoll.
* lib/mbmemcasecoll.c (apply_towlower): When mbrtowc returns 0, copy 1
byte.
* tests/test-mbmemcasecmp.h (test_ascii): Test embedded NULs.
--- lib/mbmemcasecoll.c.orig Wed Sep 22 13:31:27 2010
+++ lib/mbmemcasecoll.c Wed Sep 22 13:30:00 2010
@@ -1,5 +1,5 @@
/* Locale-specific case-ignoring memory comparison.
- Copyright (C) 2001, 2009, 2010 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2009-2010 Free Software Foundation, Inc.
Written by Bruno Haible <[email protected]>, 2001.
This program is free software: you can redistribute it and/or modify it
@@ -61,8 +61,12 @@
break;
if (n1 != (size_t)(-1))
{
- wint_t wc2 = towlower (wc1);
+ wint_t wc2;
+ if (n1 == 0) /* NUL character? */
+ n1 = 1;
+
+ wc2 = towlower (wc1);
if (wc2 != wc1)
{
size_t n2;
--- tests/test-mbmemcasecmp.h.orig Wed Sep 22 13:31:27 2010
+++ tests/test-mbmemcasecmp.h Wed Sep 22 13:21:32 2010
@@ -62,6 +62,12 @@
ASSERT (my_casecmp ("para", 4, "paragraph", 9) < 0);
ASSERT (my_casecmp ("paragraph", 9, "para", 4) > 0);
+
+ /* Embedded NULs. */
+ ASSERT (my_casecmp ("1\0", 2, "2\0", 2) < 0);
+ ASSERT (my_casecmp ("2\0", 2, "1\0", 2) > 0);
+ ASSERT (my_casecmp ("x\0""1", 3, "x\0""2", 3) < 0);
+ ASSERT (my_casecmp ("x\0""2", 3, "x\0""1", 3) > 0);
}
static void
