Subject: Re: [PATCH v2 6/6] cache-tree.c: use bug() and BUG_if_bug()

From: Junio C Hamano <[email-masked]>
Date: Wed, 01 Jun 2022 11:52:58 -0700

Ævar Arnfjörð Bjarmason  <[email-masked]> writes:

> Change "BUG" output originally added in a97e4075a16 (Keep
> rename/rename conflicts of intermediate merges while doing recursive
> merge, 2007-03-31), and later made to say it was a "BUG" in
> 19c6a4f8369 (merge-recursive: do not return NULL only to cause
> segfault, 2010-01-21) to use the new bug() function.
>
> This gets the same job done with slightly less code, as we won't need
> to prefix lines with "BUG: ". More importantly we'll now log the full
> set of messages via trace2, before this we'd only log the one BUG()
> invocation.
>
> While we're at it let's replace "There" with "there" in the message,
> i.e. not start a message with a capital letter, per the
> CodingGuidelines.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
> ---
>  cache-tree.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/cache-tree.c b/cache-tree.c
> index 6752f69d515..b91995af602 100644
> --- a/cache-tree.c
> +++ b/cache-tree.c
> @@ -692,14 +692,14 @@ struct tree* write_in_core_index_as_tree(struct repository *repo) {
>  	ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
>  	if (ret == WRITE_TREE_UNMERGED_INDEX) {
>  		int i;
> -		fprintf(stderr, "BUG: There are unmerged index entries:\n");
> +		bug("there are unmerged index entries:");
>  		for (i = 0; i < index_state->cache_nr; i++) {
>  			const struct cache_entry *ce = index_state->cache[i];
>  			if (ce_stage(ce))
> -				fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
> -					(int)ce_namelen(ce), ce->name);
> +				bug("%d %.*s", ce_stage(ce),
> +				    (int)ce_namelen(ce), ce->name);
>  		}
> -		BUG("unmerged index entries when writing inmemory index");
> +		bug("unmerged index entries when writing inmemory index");
>  	}

I do not quite understand the last change here.  Shouldn't this be
either a BUG() that flushes previous bug() or BUG_if_bug() followed
by either a BUG() or an exit()?

>  
>  	return lookup_tree(repo, &index_state->cache_tree->oid);