Re: [PATCH v2 1/2] cat-file: add mailmap support to -s option
- From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
- Date
- Sep 26, 2022, 13:16 UTC
- Message-ID
- <220926.86leq61d85.gmgdl@evledraar.gmail.com>
- In-Reply-To
- <20220926105343.233296-2-siddharthasthana31@gmail.com>
On Mon, Sep 26 2022, Siddharth Asthana wrote:
Show 53 quoted lines
> Even though the cat-file command with `-s` option does not complain when
> `--use-mailmap` option is given, the latter option is ignored. Compute
> the size of the object after replacing the idents and report it instead.
>
> In order to make `-s` option honour the mailmap mechanism we have to
> read the contents of the commit/tag object. Make use of the call to
> `oid_object_info_extended()` to get the contents of the object and store
> in `buf`. `buf` is later freed in the function.
>
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: John Cai <johncai86@gmail.com>
> Signed-off-by: Siddharth Asthana <siddharthasthana31@gmail.com>
> ---
> Documentation/git-cat-file.txt | 4 +++-
> builtin/cat-file.c | 13 +++++++++++++
> t/t4203-mailmap.sh | 10 ++++++++++
> 3 files changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
> index ec30b5c574..594b6f2dfd 100644
> --- a/Documentation/git-cat-file.txt
> +++ b/Documentation/git-cat-file.txt
> @@ -45,7 +45,9 @@ OPTIONS
>
> -s::
> Instead of the content, show the object size identified by
> - `<object>`.
> + `<object>`. If used with `--use-mailmap` option, will show the
> + size of updated object after replacing idents using the mailmap
> + mechanism.
>
> -e::
> Exit with zero status if `<object>` exists and is a valid
> diff --git a/builtin/cat-file.c b/builtin/cat-file.c
> index 989eee0bb4..9942b93867 100644
> --- a/builtin/cat-file.c
> +++ b/builtin/cat-file.c
> @@ -132,8 +132,21 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
>
> case 's':
> oi.sizep = &size;
> +
> + if (use_mailmap) {
> + oi.typep = &type;
> + oi.contentp = (void**)&buf;
> + }
> +
> if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
> die("git cat-file: could not get object info");
> +
> + if (use_mailmap && (type == OBJ_COMMIT || type == OBJ_TAG)) {
> + size_t s = size;
> + buf = replace_idents_using_mailmap(buf, &s);This is partially commentary on your already-landed series for cat-file --mailmap support. I wondered why we needed this temporary variable, and why we needed the cast_size_t_to_ulong() at all. On "master" we have a size, but e.g. for cat_one_file()'s *current* codpaths we just pass it to write_or_die().
So the net effect is that we refuse to use write_or_die() if the number in size_t doesn't fit an unsigned long, even though we never need an unsigned long in that case.
We have *other* things in the object code that need unsigned long, so it probably amounts to no practical limitation, but it's confusing & I think per [1] below we could do away with it.
There's also a subtle gotcha on "master", we replace_idents_using_mailmap() with a possibly NULL "contents", which is a misuse of the strbuf API (the "buf" member should never be NULL), but we're about to die anyway...
> + size = cast_size_t_to_ulong(s);
> + }
> +
> printf("%"PRIuMAX"\n", (uintmax_t)size);...but expanding on "master", here we have seemingly the first use of cast_size_t_to_ulong() thaht's actually needed in this file. I.e. we are about to use PRIuMAX.
But why not skip the cast(s) and make this more obvious by having the printf() argument be cast_size_t_to_ulong(size)?
In your 2/2 you then have another use of cast_size_t_to_ulong() which *is* needed in that case (we're about to stick it in a "unsigned long" member, and the "size_t s" temporary variable is also needed in that case.
1.
diff --git a/builtin/cat-file.c b/builtin/cat-file.c index 989eee0bb4c..676c34cba4b 100644 --- a/builtin/cat-file.c +++ b/builtin/cat-file.c @@ -178,11 +178,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name, if (!buf) die("Cannot read object %s", obj_name); - if (use_mailmap) { - size_t s = size; - buf = replace_idents_using_mailmap(buf, &s); - size = cast_size_t_to_ulong(s); - } + if (use_mailmap) + buf = replace_idents_using_mailmap(buf, &size); /* otherwise just spit out the data */ break; @@ -218,11 +215,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name, buf = read_object_with_reference(the_repository, &oid, exp_type_id, &size, NULL); - if (use_mailmap) { - size_t s = size; - buf = replace_idents_using_mailmap(buf, &s); - size = cast_size_t_to_ulong(s); - } + if (use_mailmap) + buf = replace_idents_using_mailmap(buf, &size); break; } default: @@ -391,12 +385,8 @@ static void print_object_or_die(struct batch_options *opt, struct expand_data *d contents = read_object_file(oid, &type, &size); - if (use_mailmap) { - size_t s = size; - contents = replace_idents_using_mailmap(contents, &s); - size = cast_size_t_to_ulong(s); - } - + if (use_mailmap) + contents = replace_idents_using_mailmap(contents, &size); if (!contents) die("object %s disappeared", oid_to_hex(oid)); if (type != data->type)