Re: A new idea to extend git-blame

From: chen bin <chenbin.sh@gmail.com>
Date: Nov 26, 2019, 04:55 UTC
Message-ID: <CAAE-R+8betprfFOH+m_mMATX2mODHQ8pFUpLo4tyLVBVAVtySg@mail.gmail.com>
In-Reply-To: <20191125141635.GD494@sigill.intra.peff.net>

I re-tested `git log -L20,20:README.md` in git's own repo with HEAD d01d26f2df. Looks git log is not what I expected. The output contains many unrelated commits. So it will be slow in real project.

A recursive blame with the algorithm I suggest will get correct commit in short time. So my suggestion still hold.

I could submit a patch to enhance blame.

On Tue, Nov 26, 2019 at 1:16 AM Jeff King <peff@peff.net> wrote:

Show 36 quoted lines

>
> On Mon, Nov 25, 2019 at 11:41:55PM +1100, Chen Bin wrote:
>
> > The key algorithm is simple,
> >
> > The algorithm only works for one line blame and the user must
> > select text inside the line first.
> >
> > Step 1, `git blame -L6,1 --porcelain -- hello.js` output,
> >
> >     4f87408612e0dacfd89a1cd2515944e21cf68561 6 6 1
> >     skip...
> >     filename hello.js
> >      doit({bad: 'destroy world', good: 'hello world', ...});
> >
> > I got the commit id (1st column), the line number (2nd column),
> > file name (hello.js) and the code line (last line).
> >
> > Step 2, if the code line does not contain the selected text, the
> >   recursive search stops
> >
> > Step 3, or else use commit id, line number and file name to build
> >   new git blame cli, like,
> >
> > `git blame -L line-num,1 --porcelain 4f8740^ file-name`
> >
> > Step 4, execute new git blame command and start from Step 1
>
> This sounds a lot like how git-log's "-L" option works, which tries to
> find the history of a line over many changes.
>
> It's also similar to the "re-blame from parent" feature of many blame
> viewers. There we have a human in the loop saying "no, this is not quite
> the change I'm looking for; go back further".
>
> -Peff

-- 
help me, help you.