[PATCH] submodule--helper: don't print null in 'submodule status'

[PATCH] submodule--helper: don't print null in 'submodule status'

[Nguyễn Thái Ngọc Duy]

The function compute_rev_name() can return NULL sometimes (e.g. right
after 'submodule init'). The current code makes 'submodule status'
print this:

 19d97bf5af05312267c2e874ee6bcf584d9e9681 sha1collisiondetection ((null))

This ugly 'null' adds no value to the user using this command. More
importantly printf() on some platform can't handle NULL as a string
and will crash instead of printing '(null)'.

Check for this and skip printing this part (the alternative is
printing '(n/a)' or something but I think that is just noise).

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 builtin/submodule--helper.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a404df3ea4..4dc7d7d29f 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -596,8 +596,12 @@ static void print_status(unsigned int flags, char state, const char *path,
 
 	printf("%c%s %s", state, oid_to_hex(oid), displaypath);
 
-	if (state == ' ' || state == '+')
-		printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
+	if (state == ' ' || state == '+') {
+		const char *name = compute_rev_name(path, oid_to_hex(oid));
+
+		if (name)
+			printf(" (%s)", name);
+	}
 
 	printf("\n");
 }
-- 
2.17.0.367.g5dd2e386c3

Re: [PATCH] submodule--helper: don't print null in 'submodule status'

[Stefan Beller]

Hi Nguyễn,

On Wed, Apr 18, 2018 at 7:53 AM, Nguyễn Thái Ngọc Duy <pclouds@gmail.com> wrote:
> The function compute_rev_name() can return NULL sometimes (e.g. right
> after 'submodule init'). The current code makes 'submodule status'
> print this:
>
>  19d97bf5af05312267c2e874ee6bcf584d9e9681 sha1collisiondetection ((null))
>
> This ugly 'null' adds no value to the user using this command. More
> importantly printf() on some platform can't handle NULL as a string
> and will crash instead of printing '(null)'.
>
> Check for this and skip printing this part (the alternative is
> printing '(n/a)' or something but I think that is just noise).

This patch restores the behavior from before a9f8a37584 (submodule:
port submodule subcommand 'status' from shell to C, 2017-10-06),
so this is the right way to go instead of the alternatives you considered.

Thanks!

Reviewed-by: Stefan Beller <sbeller@google.com>

> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
>  builtin/submodule--helper.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index a404df3ea4..4dc7d7d29f 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -596,8 +596,12 @@ static void print_status(unsigned int flags, char state, const char *path,
>
>         printf("%c%s %s", state, oid_to_hex(oid), displaypath);
>
> -       if (state == ' ' || state == '+')
> -               printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
> +       if (state == ' ' || state == '+') {
> +               const char *name = compute_rev_name(path, oid_to_hex(oid));
> +
> +               if (name)
> +                       printf(" (%s)", name);
> +       }
>
>         printf("\n");
>  }
> --
> 2.17.0.367.g5dd2e386c3
>

Re: [PATCH] submodule--helper: don't print null in 'submodule status'

[Junio C Hamano]

Stefan Beller <sbeller@google.com> writes:

> Hi Nguyễn,
>
> On Wed, Apr 18, 2018 at 7:53 AM, Nguyễn Thái Ngọc Duy <pclouds@gmail.com> wrote:
>> The function compute_rev_name() can return NULL sometimes (e.g. right
>> after 'submodule init'). The current code makes 'submodule status'
>> print this:
>>
>>  19d97bf5af05312267c2e874ee6bcf584d9e9681 sha1collisiondetection ((null))
>>
>> This ugly 'null' adds no value to the user using this command. More
>> importantly printf() on some platform can't handle NULL as a string
>> and will crash instead of printing '(null)'.
>>
>> Check for this and skip printing this part (the alternative is
>> printing '(n/a)' or something but I think that is just noise).
>
> This patch restores the behavior from before a9f8a37584 (submodule:
> port submodule subcommand 'status' from shell to C, 2017-10-06),
> so this is the right way to go instead of the alternatives you considered.
>
> Thanks!
>
> Reviewed-by: Stefan Beller <sbeller@google.com>

Excellent.  Thanks, both.

Will queue.

>
>> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
>> ---
>>  builtin/submodule--helper.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
>> index a404df3ea4..4dc7d7d29f 100644
>> --- a/builtin/submodule--helper.c
>> +++ b/builtin/submodule--helper.c
>> @@ -596,8 +596,12 @@ static void print_status(unsigned int flags, char state, const char *path,
>>
>>         printf("%c%s %s", state, oid_to_hex(oid), displaypath);
>>
>> -       if (state == ' ' || state == '+')
>> -               printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
>> +       if (state == ' ' || state == '+') {
>> +               const char *name = compute_rev_name(path, oid_to_hex(oid));
>> +
>> +               if (name)
>> +                       printf(" (%s)", name);
>> +       }
>>
>>         printf("\n");
>>  }
>> --
>> 2.17.0.367.g5dd2e386c3
>>