Re: Misrendering of git 2.25 log --graph
On Fri, Jan 24, 2020 at 01:45:34PM -0500, Derrick Stolee wrote:
Show 50 quoted lines
> On 1/24/2020 11:34 AM, Jan Engelhardt wrote:
> > On Friday 2020-01-24 15:06, Derrick Stolee wrote:
> >>
> >> I completely misread your ordering here. You are clear that this
> >> is an issue in 2.24 and NOT 2.25. Sorry.
> >>
> >> I'm not sure that there is anything to do since the graph rendering
> >> has changed so much, and we intend to keep the new version instead.
> >
> > I now have a minimized reproducer, for *2.25*:
> >
> > » ../git/git log --oneline --graph --all --decorate --topo-order
> > * e1ee7b8 (HEAD -> master) Merge branch 'k9' into k10
> > |\
> > | * 7b48214 Merge branch 'k8' into k9
> > | |\
> > | | * ed02a51 Merge branch 'blah' into k8
> > | | |\
> > | | | * 44279cf blah
> > | | * | 4053c4d Merge branch 'k7' into k8
> > | | |\ \
> > | |/ / /
> > | | | _
> > | | * 5b449d6 update 8.7 news
> > | |/
> > | * 43a324f foo
> > |/
> > * 5932a51 root
>
> Hm. I get the above output for v2.24.1. Since you are using a
> specific path for your execution, then perhaps that version
> disagrees with the one on your PATH that reported "git version"?
>
> For v2.25.0 I get this:
>
> * e1ee7b8 (HEAD -> master, origin/master, origin/HEAD) Merge branch 'k9' into k10
> |\
> | * 7b48214 Merge branch 'k8' into k9
> | |\
> | | * ed02a51 Merge branch 'blah' into k8
> | | |\
> | | | * 44279cf blah
> | | * | 4053c4d Merge branch 'k7' into k8
> | |/| |
> | | |/
> | | * 5b449d6 update 8.7 news
> | |/
> | * 43a324f foo
> |/
> * 5932a51 root
I get this good-looking graph with v2.25.0, too.
A few notes to add:
- We don't need the topmost commit e1ee7b8 to reproduce that strange
underscore below the kink with v2.24.0: $ git --no-pager log --oneline --graph --topo-order 7b48214
* 7b48214 Merge branch 'k8' into k9
|\
| * ed02a51 Merge branch 'blah' into k8
| |\
| | * 44279cf blah
| * | 4053c4d Merge branch 'k7' into k8
| |\ \
|/ / /
| | _
| * 5b449d6 update 8.7 news
|/
* 43a324f foo
* 5932a51 root - Git behaved like that up until about the middle of the patch
series simplifying the graph output, namely until commit
458152cce1 (graph: example of graph output that can be simplified,
2019-10-15). The next commit 0f0f389f12 (graph: tidy up display
of left-skewed merges, 2019-10-15) changed the bahavior for the
worse: * 7b48214 Merge branch 'k8' into k9
|\
| * ed02a51 Merge branch 'blah' into k8
| |\
| | * 44279cf blah
| * | 4053c4d Merge branch 'k7' into k8
|/|\
| |/
| * 5b449d6 update 8.7 news
|/
* 43a324f foo
* 5932a51 root Notice how 4053c4d looks like an octopus merge, and 44279cf
seemingly comes out of nowhere. And then the next commit d62893ecc1 (graph: commit and post-merge
lines for left-skewed merges, 2019-10-15) seems to have fixed this
issue, and we see the same good-looking graph that we get with
v2.25.0 as well: * 7b48214 Merge branch 'k8' into k9
|\
| * ed02a51 Merge branch 'blah' into k8
| |\
| | * 44279cf blah
| * | 4053c4d Merge branch 'k7' into k8
|/| |
| |/
| * 5b449d6 update 8.7 news
|/
* 43a324f foo
* 5932a51 root - Interestingly, the issue of an underscore below the kink is
mentioned in the later commit 92beecc136 (graph: flatten edges
that fuse with their right neighbor, 2019-10-15), quoting the last
part of its log message: One of the test cases here cannot be correctly rendered in Git v2.23.0;
it produces this output following commit E:
| | *-. \ 5_E
| | |\ \ \
| |/ / / /
| | | / _
| |_|/
|/| |
The new implementation makes sure that the rightmost edge in this
history is not left dangling as above. This is part of the new test case 'log --graph with octopus merge
with column joining its penultimate parent' in t4215 that was
added in 92beecc136. Usually when a commit both changes the code
and add new tests, then that means that that new test would have
failed on previous versions. However, that is not the case here:
I tried this new test case on earlier commits in that series, and
it already succeed with commit d62893ecc1, i.e. the same commit
that fixes Jan's cases. 
Jan Engelhardt
