Re: [PATCH] rerere: fix crash in during clear

> On Sun, Feb 18, 2024, at 12:49, Marcel Röthke wrote:
> > When rerere_clear is called, for instance when aborting a rebase, and
> > the current conflict does not have a pre or postimage recorded git
> > crashes with a SEGFAULT in has_rerere_resolution when accessing the
> > status member of struct rerere_dir. This happens because scan_rerere_dir
> > only allocates the status field in struct rerere_dir when a post or
> > preimage was found. In some cases a segfault may happen even if a post
> > or preimage was recorded if it was not for the variant of interest and
> > the number of the variant that is present is lower than the variant of
> > interest.
> >
> > This patch solves this by making sure the status field is large enough
>
> You can simplify “This patch solves this” to “Solve this”; see
> `SubmittingPatches` under “imperative-mood”.

>
> > to accommodate for the variant of interest so it can be accesses without
> > checking if it is large enough.
>
> “accessed”
>

> >
> > An alternative solution would be to always check before accessing the
> > status field, but I think the chosen solution aligns better with the
> > assumptions made elsewhere in the code.
> >
> > Signed-off-by: Marcel Röthke <marcel@roethke.info>
> > ---
> >  rerere.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/rerere.c b/rerere.c
> > index ca7e77ba68..3973ccce37 100644
> > --- a/rerere.c
> > +++ b/rerere.c
> > @@ -219,6 +219,9 @@ static void read_rr(struct repository *r, struct
> > string_list *rr)
> >  		buf.buf[hexsz] = '\0';
> >  		id = new_rerere_id_hex(buf.buf);
> >  		id->variant = variant;
> > +		/* make sure id->collection->status has enough space
> > +		 * for the variant we are interested in */
>
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