mirror of
https://github.com/git-for-windows/git.git
synced 2026-06-17 07:21:10 -05:00
53967f242a
When rendering a graph, if the history contains multiple "visual roots",
actual roots or commits that look like roots (i.e. have their parents
filtered out) can end up being vertically adjacent to unrelated commits,
falsely appearing to be related.
A fix for this issue was already attempted [1] a while ago.
This happens because the commits fill the space from left to right and
when a visual root ends, its column becomes free for the following
commit even if they are not related. Once this happens the unrelated
commit is rendered below the visual root. Because there is no special
character or way to identify when a visual root is rendered making the
graph confusing.
By indenting the visual roots when there are still commits to show the
vertical adjacency can be avoided.
Add is_visual_root flag to git_graph making it visible in all graph states,
give graph_update() a new function, graph_is_visual_root() to know if the
current commit is a visual root and set is_visual_root.
The different handled cases are:
- If a visual root has children: similar to GRAPH_PRE_COMMIT state when
octopus merges need space, an edge row needs to be printed to connect
the child with the indented visual root. A new state GRAPH_PRE_ROOT is
needed to connect the child with the visual root:
* child of the visual root
\ GRAPH_PRE_ROOT
* visual root indented
- If a visual root is child-less we can skip GRAPH_PRE_ROOT state and
render the indented commit directly.
* visual root indented
* unrelated commit
- If two or more visual roots are adjacent: by having a lookahead to the
next commit that will be rendered, if the next commit is also a visual
root and we are on a visual root, meaning two visual root adjacent in
the history, the top one can omit the indent, making the one below to
indent only once, if there are more adjacent visual commits, the
indentation will increase for each adjacent one, cascading.
* visual root
* visual root
* visual root
* last commit
Even if the last commit is a root, because there is nothing that will be
rendered below we can omit the indentation on purpose.
The lookahead is not completely reliable, on graphs with filtered parents,
the walker when processing the current commit it will simplify its
parents by removing the ones that won't be shown, (They have the
TREESAME flag when filtering by path for example), but it doesn't act
for the grandparents or the next commit if it is unrelated until we move
to the next.
For example given
A visual root
B child
C parent of B, visual root FILTERED
D last commit
We would expect
A
B
D
When processing A, for the walker and the information at the renderer, B
is still a child of C, as B parent, hasn't been removed yet. This makes
cascade to not trigger as the lookahead fails to detect if the next
commit will be a visual root.
Once at B, its parent has been removed and has become a visual root, and
it just adds its indent to the one left by A. We end up with an extra
indent:
A
B
D
The output isn't broken as unrelated commits are successfully separated
by indentation, but an indent level should have been avoided.
Create a new test file for graph indentations test called
't4218-log-graph-indentation.sh'.
The filtered parents edge case is documented as a NEEDSWORK on the
lookahead function and it has its own 'test_expect_failure' at 't4218'.
[1]: https://lore.kernel.org/git/xmqqwnwajbuj.fsf@gitster.c.googlers.com/
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
53 KiB
53 KiB