Nguyễn Thái Ngọc Duy  <[email protected]> writes:

> diff --git a/cache-tree.c b/cache-tree.c
> index 28ed657..989a7ff 100644
> --- a/cache-tree.c
> +++ b/cache-tree.c
> @@ -248,6 +248,7 @@ static int update_one(struct cache_tree *it,
>       int missing_ok = flags & WRITE_TREE_MISSING_OK;
>       int dryrun = flags & WRITE_TREE_DRY_RUN;
>       int i;
> +     int to_invalidate = 0;
>  
>       if (0 <= it->entry_count && has_sha1_file(it->sha1))
>               return it->entry_count;
> @@ -324,7 +325,13 @@ static int update_one(struct cache_tree *it,
>                       if (!sub)
>                               die("cache-tree.c: '%.*s' in '%s' not found",
>                                   entlen, path + baselen, path);
> -                     i += sub->cache_tree->entry_count - 1;
> +                     i--; /* this entry is already counted in "sub" */
> +                     if (sub->cache_tree->entry_count < 0) {
> +                             i -= sub->cache_tree->entry_count;
> +                             to_invalidate = 1;
> +                     }
> +                     else
> +                             i += sub->cache_tree->entry_count;

Hrm.  update_one() is prepared to see a cache-tree whose entry count
is zero (see the context lines in the previous hunk) and the
invariant for the rest of the code is "if 0 <= entry_count, the
cached tree is valid; invalid cache-tree has -1 in entry_count.
More importantly, entry_count negated does not in general express
how many entries there are in the subtree and does not tell us how
many index entries to skip.

> @@ -339,8 +346,23 @@ static int update_one(struct cache_tree *it,
>                               mode, sha1_to_hex(sha1), entlen+baselen, path);
>               }
>  
> -             if (ce->ce_flags & (CE_REMOVE | CE_INTENT_TO_ADD))
> -                     continue; /* entry being removed or placeholder */
> +             /*
> +              * CE_REMOVE entries are removed before the index is
> +              * written to disk. Skip them to remain consistent
> +              * with the future on-disk index.
> +              */
> +             if (ce->ce_flags & CE_REMOVE)
> +                     continue;
> +
> +             /*
> +              * CE_INTENT_TO_ADD entries exist on on-disk index but
> +              * they are not part of generated trees. Invalidate up
> +              * to root to force cache-tree users to read elsewhere.
> +              */
> +             if (ce->ce_flags & CE_INTENT_TO_ADD) {
> +                     to_invalidate = 1;
> +                     continue;
> +             }

Thanks for documenting these.

> @@ -360,7 +382,7 @@ static int update_one(struct cache_tree *it,
>       }
>  
>       strbuf_release(&buffer);
> -     it->entry_count = i;
> +     it->entry_count = to_invalidate ? -i : i;

See above.  I am not fundamentally opposed to a change to redefine
entry_count so that it always maintains how many index entries the
subtree covers, even for invalidated subtree, but I do not think
this patch alone is sufficient to maintain such invariant.

>  #if DEBUG
>       fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
>               it->entry_count, it->subtree_nr,
> diff --git a/t/t2203-add-intent.sh b/t/t2203-add-intent.sh
> index ec35409..2a4a749 100755
> --- a/t/t2203-add-intent.sh
> +++ b/t/t2203-add-intent.sh
> @@ -62,5 +62,25 @@ test_expect_success 'can "commit -a" with an i-t-a entry' '
>       git commit -a -m all
>  '
>  
> +test_expect_success 'cache-tree invalidates i-t-a paths' '
> +     git reset --hard &&
> +     mkdir dir &&
> +     : >dir/foo &&
> +     git add dir/foo &&
> +     git commit -m foo &&
> +
> +     : >dir/bar &&
> +     git add -N dir/bar &&
> +     git diff --cached --name-only >actual &&
> +     echo dir/bar >expect &&
> +     test_cmp expect actual &&
> +
> +     git write-tree >/dev/null &&
> +
> +     git diff --cached --name-only >actual &&
> +     echo dir/bar >expect &&
> +     test_cmp expect actual
> +'
> +
>  test_done
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to