Re: [GSoC RFC PATCH 0/1] graph: add indentation for commits preceded by a root

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Pablo

On 02/04/2026 22:17, Pablo Sabater wrote:
> When having a history with multiple root commits and drawing the history
> near the roots, the graphing engine renders the commit one below the other,
> seeming that they are related, which makes the graph confusing.
> 
> This issue was reported by Junio at:
>    https://lore.kernel.org/git/xmqqikaawrpx.fsf@gitster.g/
> 
> e.g.:
> 
>    * root-B
>    * child-A2
>    * child-A1
>    * root-A
> 
> [...]
 >
>    * root-B
>      * child-A2
>     /
>    * child-A1
>    * root-A

I'm rather late to the party here, but personally I find the indentation 
a bit confusing, it would be clearer to me if we had a blank line after 
a root commit

     * root-B

     * child-A2
     * child-A1
     * root-A

It takes the same amount of vertical space but keeps the children of 
root-A together.

Thanks

Phillip

> This is done by adding a is_placeholder flag to the columns, the root commit
> is actually there but marked as a placeholder
> 
> e.g.:
> 
>     * root-B
>    (B) * child-A2
>      /
>     * child-A1
>     * root-A
> 
> (B) would be root-B column with the placeholder flag active.
> 
> Then teaching the rendering function to print a padding ' ' when meeting a
> placeholder column outputs the second example.
> 
> There could also be the case where there are multiple roots
> 
> without the patch:
> 
>    * A root
>    * B root
>    * C root
>    * D1 child
>    * D root
> 
> with the patch, the indentation cascades:
> 
>    * A root
>      * B root
>        * C root
>          * D1 child
>       _ /
>      /
>     /
>    * D root
> 
> the _ / might look weird but that's how the collapsing rendering does it
> for big gaps, this case being from the 4th column to the 0th column.
> Another patch could change the collapsing rendering for placeholders ?
> I haven't done it to keep it minimal, but a follow up could make it
> to be straight '/'. This would make it bigger but easier for the eye to follow.
> IMO is not worth it, but opinions are welcome.
> 
> The patch also adds tests for different cases like a root preceding multiple
> parents merges and the examples above.
> 
> There could be some edge cases still so any testing is very welcome.
> 
> Pablo Sabater (1):
>    graph: add indentation for commits preceded by a root
> 
>   graph.c                      |  68 ++++++++++++++++--
>   t/t4215-log-skewed-merges.sh | 136 +++++++++++++++++++++++++++++++++++
>   2 files changed, 198 insertions(+), 6 deletions(-)
> 
> 
> base-commit: 256554692df0685b45e60778b08802b720880c50