Re: [PATCH] Allow emails with boundaries to work again [v2]

> Recent changes to is_multipart_boundary() caused git-mailinfo to  
> segfault.
> The reason was after handling the end of the boundary the code tried  
> to look
> for another boundary.  Because the boundary list was empty,  
> dereferencing
> the pointer to the top of the boundary caused the program to go boom.
>
> The fix is to check to see if the list is empty and if so go on its  
> merry
> way instead of looking for another boundary.
>
> I also fixed a couple of increments and decrements that didn't look  
> correct
> relating to content_top.
>
> The boundary test case was updated to catch future problems like  
> this again.
>
> Signed-Off-by: Don Zickus <dzickus@redhat.com>
>
> ---
> Junio,
>
> I modified the patch more to your liking, I think.  You inquired about
> returning after failing from find_boundary() and I gave you a not so  
> correct
> answer.  Once I re-read the code this morning (minus a screaming kid  
> in the
> background), I realized it was easy to do and more correct.
>
> I also figured out why the boundary test case didn't catch this.   
> Apparently
> find_boundary() went to read another line and found none, so it  
> returned 0.
> Adding an empty line to sample.mbox, caused git-mailinfo to segfault  
> like
> the way I saw it.  My fix allows everything to work again.
>
> Cheers,
> Don
> ---
> builtin-mailinfo.c  |    6 +++---
> t/t5100/sample.mbox |    1 +
> 2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/builtin-mailinfo.c b/builtin-mailinfo.c
> index 6ae2bf3..207d0ef 100644
> --- a/builtin-mailinfo.c
> +++ b/builtin-mailinfo.c
> @@ -175,7 +175,7 @@ static void handle_content_type(struct strbuf  
> *line)
> 		 message_type = TYPE_OTHER;
> 	if (slurp_attr(line->buf, "boundary=", boundary)) {
> 		strbuf_insert(boundary, 0, "--", 2);
> -		if (content_top++ >= &content[MAX_BOUNDARIES]) {
> +		if (++content_top > &content[MAX_BOUNDARIES]) {
> 			fprintf(stderr, "Too many boundaries to handle\n");
> 			exit(1);
> 		}
> @@ -603,7 +603,7 @@ static void handle_filter(struct strbuf *line);
> static int find_boundary(void)
> {
> 	while (!strbuf_getline(&line, fin, '\n')) {
> -		if (is_multipart_boundary(&line))
> +		if (*content_top && is_multipart_boundary(&line))
> 			return 1;
> 	}
> 	return 0;
> @@ -626,7 +626,7 @@ again:
> 		/* technically won't happen as is_multipart_boundary()
> 		   will fail first.  But just in case..
> 		 */
> -		if (content_top-- < content) {
> +		if (--content_top < content) {
> 			fprintf(stderr, "Detected mismatched boundaries, "
> 					"can't recover\n");
> 			exit(1);
> diff --git a/t/t5100/sample.mbox b/t/t5100/sample.mbox
> index d7ca79b..4bf7947 100644
> --- a/t/t5100/sample.mbox
> +++ b/t/t5100/sample.mbox
> @@ -500,3 +500,4 @@ index 3e5fe51..aabfe5c 100644
> 1.6.0.rc2
>
> --=-=-=--
> +
> -- 
> 1.5.5.1
>
> --
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