On 2022/08/17 15:49:57 +0200, Stefan Sperling <stsp@stsp.name> wrote:
> On Tue, Aug 16, 2022 at 11:42:46PM +0200, Omar Polo wrote:
> > found that some hours ago gotwebd crashed.  I'm running gotwebd as of
> > bf80b15220f51490025e916633cdd70816113604 ("gotwebd: fix alternate
> > colors in tree entries") plus the fcgi_printf and the fix for the
> > double free on gotweb_free_querystring.
> > 
> > can't study the stacktrace now, will do that tomorrow when I have
> > time, but in the meantime I'm sharing it in case it rings some bells :)
> 
> Try the patch below.
> If this is indeed the bug, then it also exists in got/got.c.

I found how to reproduce the bug with `got blame', but interestingly
it doesn't happen with `tog blame'!

The diff doesn't help

Program received signal SIGSEGV, Segmentation fault.
0x000007ec6721f72f in blame_cb (arg=0x7f7fffff2d58, nlines=512, lineno=512,
    commit=0x7eeb31bf780, id=0x7eed27b1a40) at /home/op/w/got/got/got.c:5369
5369            while (bline->annotated && a->lineno_cur <= a->nlines) {
(gdb) p *bline
Cannot access memory at address 0x7ef290b3000
(gdb) p *a
$1 = {lines = 0x7ef290ae000, nlines = 512, nlines_prec = 3, lineno_cur = 513,
  line_offsets = 0x7ee6775a000, f = 0x7ee68a93028 <usual+152>, repo = 0x7eeb31cb520}

> diff /home/stsp/src/got
> commit - 4fcc9f7404ca2e0dd2ee085f09d6246587c6c503
> path + /home/stsp/src/got
> blob - 1c274b225d0e710d16528c4b9970348bb3bec74e
> file + gotwebd/got_operations.c
> --- gotwebd/got_operations.c
> +++ gotwebd/got_operations.c
> @@ -1334,7 +1334,7 @@ got_gotweb_blame_cb(void *arg, int nlines, int lineno,
>  		goto done;
>  	}
>  
> -	while (bline->annotated) {
> +	while (bline->annotated && a->lineno_cur <= a->nlines) {

I can avoid the crash by changing the <= to < but then the last line
is not print...  There has to be an off by one somewhere, I don't have
the time right now to track this further, sorry :(

I'm able to reproduce it using

$ got blame -c 72e7fbbcb7740a86e44d043727782b50356dd69d ChangeLog

in my gmid repo, available at:

git://git.omarpolo.com/gmid.git
https://git.omarpolo.com/gmid.git