Re: [PATCH 1/2] revision: Denote root commits with '#'

Kyle Marek <kmarek@pdinc.us> writes:

The "current graph layout makes it harder to see where the root is" problem has a natural solution: fix the graph layout so that the root is easily visible.

I however think it is a much harder approach to solve than using a different mark for root commits, and it is the reason why there have been at least a few attempts in the past that did essentially the same patch as yours, plus the "linear break" which we accepted.

Sorry, I am not quite sure what you are trying to illustrate with the comparison between the above two. The latter makes it clear that 9203a43 and da85ccf do not have parents in the depicted part of the history [*1*].

In the former one, does 2237b52 have no child in the depicted part of the history, and is the problem that it appears as if it has a674e07 as a child? I wonder if we can just shift them, either:

or

Or we could punt to show it with an extra blank line, although it is suboptimial.

[Footnote]

*1* Stepping back a bit, I think concentrating too much on "is it
    root?" is a wrong way to think about the problem.  Suppose you
    have two histories, e.g. (time flows from left to right; A and X
    are roots)

            A---B
                 \
          X---Y---Z

    and doing "git log --graph --oneline Z" would show A, B, X, Y
    and Z.

    If it benefits to show "A" (and "X") specially in the graph,
    that would mean that the current algorithm would show some other
    commit after showing A (probably X if it goes in chronological
    order), and it probably is confusing because X is shown on the
    same column as A, when there is no parent-child relationship
    between them (A is root after all).

    We are trying to highlight that A is not a child of anybody by
    using '#' instead.

    But in a slightly modified graph:

          C
         /
        O---A---B
                 \
          X---Y---Z

    if you do "git log --graph --oneline C..Z", you should see the
    same commits listed as above (A, B, X, Y and Z), and most likely
    in the same order.

    So special casing by "Ah, A is a root commit, so let's show it
    with '#'" does not help, even though we are facing exactly the
    same problem in the latter graph.

    And the right way to look at it is "does A have any parent in
    the part of the history being shown?", not "does A have any
    parent?"  Then 'A' will get exactly the same treatment in the
    two examples, and the visual problem that makes A appear as if
    it has parent-child relationship with unrelated commit X goes
    away.