referencing one commit in another for git

[Jan Beich]

Warner Losh <imp at bsdimp.com> writes:

> On Wed, Dec 23, 2020, 3:21 PM Alan Somers <asomers at freebsd.org> wrote:
>
>> On Wed, Dec 23, 2020 at 3:16 PM Rick Macklem <rmacklem at uoguelph.ca> wrote:
>>
>> > Hi,
>> >
>> > So I just did my first git commit. Pretty scary, but it looks ok.
>> >
>> > Now, how do I reference one commit in another related
>> > commit's log?
>> >
>> > By the long winded hash or ??
>> >
>> > I'm not sure if I should ask here or on the git mailing list,
>> > but I figured this isn't a technical git question...
>> >
>> > Thanks for any help with this, rick
>> >
>>
>> Yeah, you should use the full hash.  For temporary references, like during
>> a code review, you can use the first "several" digits of the hash.   For a
>> project of FreeBSD's size, "several" is probably 11-13.  But in permanent
>> contexts, like commit logs, you should use the full hash.  When somebody
>> views the commit on a platform like Github, Github will automatically turn
>> it into a hyperlink, and display only the first "several" digits.
>>
>
>
> For MFCs we are recommending the first 11. I think this will likely suffice
> and matches the git client behavior.

Mercurial defaults to 12 digit abbreviation. Git abbreviates linux,
freebsd-legacy, freebsd-ports repos on GitHub to 12 digit.