Re: bug in memcoll module (+ another sync from coreutils)

[Paul Eggert]

Bruno Haible <address@hidden> writes:

> IMO, the fix depends whether you trust memcmp() these days.
> If yes, then do not require AC_FUNC_MEMCMP.
> If no, then make a dependency from 'memcoll' to 'memcmp'. And then you don't
>        need to require AC_FUNC_MEMCMP either, since the gnulib-tool
>        dependency mechanism will take care of invoking gl_FUNC_MEMCMP.

I Googled around for memcmp failures and found only apparent failure
that autoconf found (in BSD/OS in 2000, which is a bit marginal; see
<http://groups.google.com/group/comp.lang.perl.modules/msg/bb85f1db96a45959>)
so I think we can leave this up to each individual maintainer, most of
whom won't care.

> In either case, the appended patch should be part of the fix.

Thanks.  I installed that.  I also synced today's coreutils fixes,
as follows:

2006-01-10  Jim Meyering  <address@hidden>

        Avoid the double-free (first in fts_read, second in fts_close) that
        would occur when an `active' directory is made inaccessible (e.g.,
        via chmod a-x) during a traversal.
        * lib/fts.c (fts_read): After a failed fchdir, update sp->fts_cur
        before returning.  Reproduce this failure by
        mkdir -p a/b; cd a; chmod a-x . b
        Reported by Stavros Passas.
        * lib/sha1.c: Tweak grammar in a comment.

        * m4/fpending.m4: Also include <stdio.h>, for Dragonfly.
        Patch by Joerg Sonnenberger.

        * m4/memcoll.m4 (gl_MEMCOLL): Don't require AC_FUNC_MEMCMP, undoing
        the 2002-12-31 change.  Problem and fix reported by Bruno Haible.
        People who are still concerned with buggy memcmp implementations
        can invoke gl_FUNC_MEMCMP themselves.

--- lib/fts.c   9 Jan 2006 23:13:56 -0000       1.8
+++ lib/fts.c   10 Jan 2006 21:27:33 -0000
@@ -522,6 +522,7 @@ next:       tmp = p;
                if (p->fts_level == FTS_ROOTLEVEL) {
                        if (FCHDIR(sp, sp->fts_rfd)) {
                                SET(FTS_STOP);
+                               sp->fts_cur = p;
                                return (NULL);
                        }
                        fts_load(sp, p);
--- lib/sha1.c  17 Oct 2005 12:55:00 -0000      1.5
+++ lib/sha1.c  10 Jan 2006 21:27:33 -0000
@@ -77,7 +77,7 @@ sha1_init_ctx (struct sha1_ctx *ctx)
    must be in little endian byte order.
 
    IMPORTANT: On some systems it is required that RESBUF is correctly
-   aligned for a 32 bits value.  */
+   aligned for a 32-bit value.  */
 void *
 sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
 {
@@ -94,7 +94,7 @@ sha1_read_ctx (const struct sha1_ctx *ct
    prolog according to the standard and write the result to RESBUF.
 
    IMPORTANT: On some systems it is required that RESBUF is correctly
-   aligned for a 32 bits value.  */
+   aligned for a 32-bit value.  */
 void *
 sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
 {
--- m4/fpending.m4      30 Oct 2005 23:06:58 -0000      1.13
+++ m4/fpending.m4      10 Jan 2006 21:27:33 -0000
@@ -1,6 +1,6 @@
-#serial 7
+#serial 8
 
-# Copyright (C) 2000, 2001, 2004, 2005 Free Software Foundation, Inc.
+# Copyright (C) 2000, 2001, 2004, 2005, 2006 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
@@ -20,6 +20,7 @@ AC_DEFUN([gl_FUNC_FPENDING],
   AC_CHECK_HEADERS(stdio_ext.h)
   AC_REPLACE_FUNCS([__fpending])
   fp_headers='
+#     include <stdio.h>
 #     if HAVE_STDIO_EXT_H
 #      include <stdio_ext.h>
 #     endif
--- m4/memcoll.m4       21 Mar 2005 22:06:27 -0000      1.5
+++ m4/memcoll.m4       10 Jan 2006 21:34:38 -0000      1.7
@@ -1,5 +1,5 @@
-# memcoll.m4 serial 5
-dnl Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc.
+# memcoll.m4 serial 6
+dnl Copyright (C) 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -10,6 +10,5 @@ AC_DEFUN([gl_MEMCOLL],
   AC_LIBOBJ([memcoll])
 
   dnl Prerequisites of lib/memcoll.c.
-  AC_REQUIRE([AC_FUNC_MEMCMP])
   AC_FUNC_STRCOLL
 ])