RE: [PATCH] revisions(7): clarify that most commands take a single revision range

From: Felipe Contreras <felipe.contreras@gmail.com>
Date: May 21, 2021, 19:19 UTC
Message-ID: <60a807b82f6aa_558062081c@natae.notmuch>
In-Reply-To: <xmqqv97g2svd.fsf@gitster.g>

Junio C Hamano wrote:

> +Commands that are specifically designed to take two distinct ranges
> +(e.g. "git range-diff R1 R2" to compare two ranges) do exist, but
> +they are exceptions.  Unless otherwise noted, all "git" commands

Not sure why "git" is in quotes.

Show 15 quoted lines

> +that operate on a set of commits work on a single revision range.
> +In other words, writing two "two-dot range notation" next to each
> +other, e.g.
> +
> +    $ git log A..B C..D
> +
> +does *not* specify two revision ranges for most commands.  Instead
> +it will name a single connected set of commits, i.e. those that are
> +reachable from either B or D but are reachable from neither A or C.
> +In a linear history like this:
> +
> +    ---A---B---o---o---C---D
> +
> +because A and B are reachable from C, the revision range specified
> +by these two dotted ranges is a single commit D.

  For example, if you have a linear history like this:

    ---A---B---C---D---E---F

  Doing A..F will retrieve 5 commits, and doing B..E will retrieve 3
  commits, but doing A..F B..E will not retrieve 8 commits. Instead the
  starting point A gets overriden by B, and the ending point of E by F,
  effectively becoming B..F.

  With more complex graphs the result is not so simple and might result
  in two disconnected sets of commits, but that is considered a single
  revision range.

-- 
Felipe Contreras