When a merge commit is printed and its final parent is the same commit
that occupies the column to the right of the merge, this results in a
kink in the displayed edges:
* |
|\ \
| |/
| *
Graphs containing these shapes can be hard to read, as the expansion to
the right followed immediately by collapsing back to the left creates a
lot of zig-zagging edges, especially when many columns are present.
We can improve this by eliminating the zig-zag and having the merge's
final parent edge fuse immediately with its neighbor:
* |
|\|
| *
This reduces the horizontal width for the current commit by 2, and
requires one less row, making the graph display more compact. Taken in
combination with other graph-smoothing enhancements, it greatly
compresses the space needed to display certain histories:
*
|\
| * *
| |\ |\
| | * | *
| | | | |\
| | \ | | *
| *-. \ | * |
| |\ \ \ => |/|\|
|/ / / / | | *
| | | / | * |
| | |/ | |/
| | * * /
| * | |/
| |/ *
* |
|/
*
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.
Signed-off-by: James Coglan <jcoglan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a graph contains edges that are in the process of collapsing to the
left, but those edges cross a commit line, the effect is that the edges
have a jagged appearance:
*
|\
| *
| \
*-. \
|\ \ \
| | * |
| * | |
| |/ /
* | |
|/ /
* |
|/
*
We already takes steps to smooth edges like this when they're expanding;
when an edge appears to the right of a merge commit marker on a
GRAPH_COMMIT line immediately following a GRAPH_POST_MERGE line, we
render it as a `\`:
* \
|\ \
| * \
| |\ \
We can make a similar improvement to collapsing edges, making them
easier to follow and giving the overall graph a feeling of increased
symmetry:
*
|\
| *
| \
*-. \
|\ \ \
| | * |
| * | |
| |/ /
* / /
|/ /
* /
|/
*
To do this, we introduce a new special case for edges on GRAPH_COMMIT
lines that immediately follow a GRAPH_COLLAPSING line. By retaining a
copy of the `mapping` array used to render the GRAPH_COLLAPSING line in
the `old_mapping` array, we can determine that an edge is collapsing
through the GRAPH_COMMIT line and should be smoothed.
Signed-off-by: James Coglan <jcoglan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Also move repeated tag and branch deletions into a separate setup test, to
avoid failures from tags and branches having already been deleted.
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These tests help make sure graph_is_interesting() is doing the right
thing.
Signed-off-by: Adam Simpkins <simpkins@facebook.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
