For example,
```
<<<<<<< Conflict 1 of 3
+++++++ Contents of side #1
left 3.1
left 3.2
left 3.3
%%%%%%% Changes from base to side #2
-line 3
+right 3.1
>>>>>>>
```
or
```
<<<<<<< Conflict 1 of 1
%%%%%%% Changes from base to side #1
-line 3
+right 3.1
+++++++ Contents of side #2
left 3.1
left 3.2
left 3.3
>>>>>>>
```
Currently, there is no way to disable these, this is TODO for a future
PR. Other TODOs for future PRs: make these labels configurable. After
that, we could support a `diff3/git`-like conflict format as well, in
principle.
Counting conflicts helps with knowing whether you fixed all the
conflicts while you are in the editor.
While labeling "side #1", etc, does not tell you the commit id or
description as requested in #1176, I still think it's an improvement.
Most importantly, I hope this will make `jj`'s conflict format less
scary-looking for new users.
I've used this for a bit, and I like it. Without the labels, I would see
that the two conflicts have a different order of conflict markers, but I
wouldn't be able to remember what that means. For longer diffs, it can
be tricky for me to quickly tell that it's a diff as opposed to one of
the sides. This also creates some hope of being able to navigate a
conflict with more than 2 sides.
Another not-so-secret goal for this is explained in
https://github.com/martinvonz/jj/pull/3109#issuecomment-2014140627. The
idea is a little weird, but I *think* it could be helpful, and I'd like
to experiment with it.
I've heard of one instance of a person being confused by the error.
Previously, the error was:
```
Error: Failed to load tool configuration
Caused by: To use `diffedit3` as a merge tool, the config `merge-tools.diffedit3.merge-args` must be defined (see docs for details)
```
Now, it is:
```
Error: The tool `diffedit3` cannot be used as a merge tool with `jj resolve`.
Hint: To use `diffedit3` as a merge tool, the config `merge-tools.diffedit3.merge-args` must be defined (see docs for details)
```
TODO for future PR: allow setting `merge-tools.TOOL.edit-args = false` so that
attempting to use TOOL as a diff editor fails. This would be helpful, for
example, for the `vscode` tool.
I considered adding RefTarget template type, but some of the methods naturally
fit to RefName. For example, a conflicted branch name is decorated as "??", so
it makes sense to add branch.conflict() instead of branch.target().conflict().
I'm not pretty sure how many RefName methods we'll need to add to port the
current branch listing, but there will be .tracked(), .tracking_local_present(),
.ahead_by(), and .behind_by().
I'm going to add more detailed output there. This is a step towards "branch
list" template. "tag list -T" wouldn't be that useful, but it shares primitives
with "branch list -T".
I'm going to add ref_name.target*() template methods so the commit templater
can be reused for branches/tags templates. RefTarget could be looked up by
(name, kind) pair, but it's simpler to store it in RefName.
Before this patch, we would abandon the source commit if it became
empty after applying the reverse diff. This changes that condition to
the equivalent condition of the selected tree being the source
commit's original tree. This will help us rewrite the code to use
`transform_descendants()`.
The `move_commits` function accepts a set of target commits to shift to
a new location given by `new_parents` and `new_children`. The roots of
the target set will be reparented onto `new_parents`. `new_children`
will then be reparented onto the heads of the target set.
The commits will be rebased in reverse topological order based on the
new set of parents of each commit, which avoids the need for multiple
sets of rebase operations.
Spotted while experimenting with "jj tag list -T". The description_placeholder
alias could be changed to function taking a Commit object, but I feel it's odd.
Conceptually, the placeholder could also be used in "op log" templates.
