Re* [PATCH v4] submodule: port subcommand 'set-url' from shell to C

From: Junio C Hamano <gitster@pobox.com>
Date: May 8, 2020, 15:18 UTC
Message-ID: <xmqq8si21mlz.fsf_-_@gitster.c.googlers.com>
In-Reply-To: <CAP8UFD0=_8D8hkT5VVPV_F++dr131bkjby357fA+QfhQxktcMg@mail.gmail.com>

Christian Couder <christian.couder@gmail.com> writes:

Show 14 quoted lines

> On Fri, May 8, 2020 at 7:51 AM Shourya Shukla
> <shouryashukla.oo@gmail.com> wrote:
>>
>> On 06/05 10:08, Junio C Hamano wrote:
>
>> > Specifically, I would write "!path", not "path == NULL".  I thought
>> > a rule for that is in the CodingGuidelines (I didn't double check,
>> > though).
>>
>> I could not find a rule like that in the CodingGuidelines.
>> Should I add it?
>> https://github.com/git/git/blob/master/Documentation/CodingGuidelines
>
> Sure.

I'd rather not see too many unrelated things piled up on Shourya's plate. Without guidance, the new entry we'll see would be only about comparing with NULL, and we'd need to spend review cycles correcting that, too.

How about something like this, perhaps?

-- >8 --
CodingGuidelines: do not ==/!= compare with 0/NULL

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/CodingGuidelines | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 390ceece52..41a89dd845 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -236,6 +236,19 @@ For C programs:
         while( condition )
 		func (bar+1);
 
+ - Do not explicitly compare an integral value with constant 0 or a
+   pointer value with constant NULL for equality; just say !value
+   instead.  To validate a counted array at ptr that has cnt elements
+   in it, write:
+
+	if (!ptr || !cnt)
+		BUG("array should not be empty at this point");
+
+   and not:
+
+	if (ptr == NULL || cnt == 0);
+		BUG("array should not be empty at this point");
+
  - We avoid using braces unnecessarily.  I.e.
 
 	if (bla) {