Eric Blake wrote:
> On 09/04/2012 04:57 AM, Eric Blake wrote:
>>> * lib/fts.c (fts_open): Upon initialization, if a name ends in two
>>> or more slashes, trim all but the final one. But if a name consists
>>> solely of two or more slashes, reduce it to "//", not to "/".
>>>
>>
>> For two slashes, that is correct. But trimming "///" to "//" is a
>> violation of POSIX and fails on cygwin; "///" must be the same as "/",
>> not "///".
>>
>>> +++ b/lib/fts.c
>>> @@ -487,6 +487,14 @@ fts_open (char * const *argv,
>>> for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
>>> /* *Do* allow zero-length file names. */
>>> size_t len = strlen(*argv);
>>> +
>>> + /* If there are two or more trailing slashes, trim all but
>>> one,
>>> + but don't change "//" to "/". */
>>> + char const *v = *argv;
>>> + if (2 < len && v[len - 1] == '/')
>>> + while (2 < len && v[len - 2] == '/')
>>> + --len;
>
> I think that this would do the right thing, though (notice that it
> strips all but 1 slash for anything longer than "//" to begin with):
>
> + char const *v = *argv;
> + if (2 < len && v[len - 1] == '/')
> + while (1 < len && v[len - 1] == '/')
> + --len;
Here's the revised commit:
>From 3a9002d3cc63da7110f133b1040d2d2b0aad8305 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyer...@redhat.com>
Date: Tue, 4 Sep 2012 11:36:38 +0200
Subject: [PATCH] fts: reduce two or more trailing slashes to just one,
usually
* lib/fts.c (fts_open): Upon initialization, if a name ends in two
or more slashes, trim all but the final one. But if a name consists
solely of two slashes, don't modify it. If it consists solely of
three or more slashes, strip all but one.
This is part of the solution to a minor problem with rm:
it would print a bogus ELOOP diagnostic when failing to remove
the slash-decorated name of a symlink-to-directory:
$ mkdir d && ln -s d s && env rm -r s/
rm: cannot remove 's': Too many levels of symbolic links
With the change below and a trivial don't-trim-trailing-slashes
adjustment to remove.c, it does this:
$ env rm -r s/
rm: cannot remove 's/': Not a directory
Improved by: Eric Blake
---
ChangeLog | 21 +++++++++++++++++++++
lib/fts.c | 8 ++++++++
2 files changed, 29 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index d4d2cb1..0874c81 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,26 @@
2012-09-04 Jim Meyering <meyer...@redhat.com>
+ fts: reduce two or more trailing spaces to just one, usually
+ * lib/fts.c (fts_open): Upon initialization, if a name ends in two
+ or more slashes, trim all but the final one. But if a name consists
+ solely of two slashes, don't modify it. If it consists solely of
+ three or more slashes, strip all but one.
+
+ This is part of the solution to a minor problem with rm:
+ it would print a bogus ELOOP diagnostic when failing to remove
+ the slash-decorated name of a symlink-to-directory:
+
+ $ mkdir d && ln -s d s && env rm -r s/
+ rm: cannot remove 's': Too many levels of symbolic links
+
+ With the change below and a trivial don't-trim-trailing-slashes
+ adjustment to remove.c, it does this:
+
+ $ env rm -r s/
+ rm: cannot remove 's/': Not a directory
+
+ Improved by: Eric Blake
+
fts: when there is no risk of overlap, use memcpy, not memmove
* lib/fts.c (fts_alloc): Fix unjustified memcopy: s/memmove/memcpy/
diff --git a/lib/fts.c b/lib/fts.c
index ce14a80..36f7e0d 100644
--- a/lib/fts.c
+++ b/lib/fts.c
@@ -487,6 +487,14 @@ fts_open (char * const *argv,
for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
/* *Do* allow zero-length file names. */
size_t len = strlen(*argv);
+
+ /* If there are two or more trailing slashes, trim all but one,
+ but don't change "//" to "/", and do map "///" to "/". */
+ char const *v = *argv;
+ if (2 < len && v[len - 1] == '/')
+ while (1 < len && v[len - 2] == '/')
+ --len;
+
if ((p = fts_alloc(sp, *argv, len)) == NULL)
goto mem3;
p->fts_level = FTS_ROOTLEVEL;
--
1.7.12.176.g3fc0e4c
