On Wed, Mar 21 2018, Jeff King wrote:

On Sun, Mar 18, 2018 at 03:25:15PM +0100, Nguyễn Thái Ngọc Duy wrote:

quoted

v6 fixes the one optimization that I just couldn't get right, fixes
two off-by-one error messages and a couple commit message update
(biggest change is in 11/11 to record some numbers from AEvar)

[...]Yes, having that many packs is insane, but that's going to be
small consolation to somebody whose automated maintenance program now
craps out at 16k packs, when it previously would have just worked to
fix the situation[...]

That's going to be super rare (and probably nonexisting) edge case, but
(untested) I wonder if something like this on top would alleviate your
concerns, i.e. instead of dying we just take the first N packs up to our
limit:

    diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
    index 4406af640f..49d467ab2a 100644
    --- a/builtin/pack-objects.c
    +++ b/builtin/pack-objects.c
    @@ -1065,8 +1065,9 @@ static int want_object_in_pack(const struct object_id *oid,

            want = 1;
     done:
    -       if (want && *found_pack && !(*found_pack)->index)
    -               oe_add_pack(&to_pack, *found_pack);
    +       if (want && *found_pack && !(*found_pack)->index) {
    +               if (oe_add_pack(&to_pack, *found_pack) == -1)
    +                       return 0;

            return want;
     }
    diff --git a/pack-objects.h b/pack-objects.h
    index 9f8e450e19..50ed2028fb 100644
    --- a/pack-objects.h
    +++ b/pack-objects.h
    @@ -171,15 +171,17 @@ static inline void oe_set_in_pack_pos(const struct packing_data *pack,
            pack->in_pack_pos[e - pack->objects] = pos;
     }

    -static inline unsigned int oe_add_pack(struct packing_data *pack,
    +static inline int oe_add_pack(struct packing_data *pack,
                                           struct packed_git *p)
     {
    -       if (pack->in_pack_count >= (1 << OE_IN_PACK_BITS))
    -               die(_("too many packs to handle in one go. "
    -                     "Please add .keep files to exclude\n"
    -                     "some pack files and keep the number "
    -                     "of non-kept files below %d."),
    +       if (pack->in_pack_count >= (1 << OE_IN_PACK_BITS)) {
    +               warning(_("Too many packs to handle in one go. "
    +                         "Ran into the limit of %d.\n"
    +                         "Limping along by pretending packs beyond that"
    +                         "number have *.keep!"),
                        1 << OE_IN_PACK_BITS);
    +               return -1;
    +       }
            if (p) {
                    if (p->index > 0)
                            die("BUG: this packed is already indexed");