[PATCH] diff: strip trailing / on dirs

[Matheus Izvekov]

On 09:40 Fri 09 Jul     , Natanael Copa wrote:
> fixes #2203
> https://bugs.busybox.net/show_bug.cgi?id=2203
> ---
>  editors/diff.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/editors/diff.c b/editors/diff.c
> index 07594e8..e2da626 100644
> --- a/editors/diff.c
> +++ b/editors/diff.c
> @@ -788,9 +788,15 @@ static void diffdir(char *p[2], const char *s_start)
>  
>  	memset(&list, 0, sizeof(list));
>  	for (i = 0; i < 2; i++) {
> +		char *lc;
>  		/*list[i].s = list[i].e = 0; - memset did it */
>  		/*list[i].dl = NULL; */
>  
> +		/* trim trailing / in dirs. */
> +		lc = last_char_is(p[i], '/');
> +		if (lc && lc != p[i])
> +			*lc = '\0';
> +
>  		/* We need to trim root directory prefix.
>  		 * Using list.len to specify its length,
>  		 * add_to_dirlist will remove it. */
> -- 
> 1.7.1.1
> 
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Thanks for reporting that bug!
Besides stripping only one slash, as Bernhard pointed out, the
problem with this patch is that it directly modifiles the file names
stored in argv, so in case the files do differ, the headers are wrong.
Consider this output from gnu diff:
  % diff -ur diff1 diff2/////
  diff -ur diff1/test diff2//////test
  --- diff1/test  2010-07-09 12:26:55.248987189 -0300
  +++ diff2//////test     2010-07-09 11:26:08.454402145 -0300

Notice the slashes are preserved in the header.

The patch below should fix the issue properly, but please do test!

---

Subject: [PATCH] diff: fix for trailing slashes (bugzilla #2203)
Cc: busybox at busybox.net

Signed-off-by: Matheus Izvekov <mizvekov at gmail.com>
---
 editors/diff.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/editors/diff.c b/editors/diff.c
index 07594e8..8d91b83 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -760,9 +760,11 @@ static int FAST_FUNC add_to_dirlist(const char *filename,
 		void *userdata, int depth UNUSED_PARAM)
 {
 	struct dlist *const l = userdata;
+	const char *file = filename + l->len;
 	l->dl = xrealloc_vector(l->dl, 6, l->e);
-	/* + 1 skips "/" after dirname */
-	l->dl[l->e] = xstrdup(filename + l->len + 1);
+	while(*file == '/')
+		file++;
+	l->dl[l->e] = xstrdup(file);
 	l->e++;
 	return TRUE;
 }
-- 
1.7.1.1