localrepo: delete obsolete comment about `prefix in repo` raising exception
We dropped support for `prefix in repo`, where `prefix` is a hex
prefix, in
8b86acc7aa64 (context: drop support for looking up context
by ambiguous changeid (API), 2018-04-28), after having deprecated it a
while before that. These days you get a `ProgrammingError` instead if
you pass in a short nodeid.
Differential Revision: https://phab.mercurial-scm.org/D9599
node: import symbols explicitly
There is no point in lazy importing mercurial.node, it is used all over
the place anyway. So consistently import the used symbols directly.
Fix one file using symbols indirectly via mercurial.revlog.
Differential Revision: https://phab.mercurial-scm.org/D9480
debugdiscovery: fix swapped heads and roots
Patch provided without comment…
Differential Revision: https://phab.mercurial-scm.org/D9566
debugdiscovery: display the number of roundtrip used
This is a good metric of the complexity of a discovery process.
Differential Revision: https://phab.mercurial-scm.org/D9565
copies: make calculating lazy for dir move detection's "addedfiles"
The information calculated here was only needed if (a) --debug was specified, or
(b) a directory move was plausibly detected. With tree manifests (especially in
my pathological repo and with our custom setup), pre-calculating the `u1` and
`u2` can be quite slow, and it's not even necessary in many cases. Let's delay
calculating it until we know it's actually necessary. This should have no
observable differences in output.
### Performance
I ran a rebase command in my pathological repo, rebasing two nodes across
several public phase commits, but where no directory copies exist in any of the
paths I'm tracking.
#### Before
```
Time (mean ± σ): 3.711 s ± 0.061 s [User: 0.3 ms, System: 1.5 ms]
Range (min … max): 3.640 s … 3.827 s 10 runs
```
#### After
```
Time (mean ± σ): 868.3 ms ± 10.1 ms [User: 0.5 ms, System: 1.2 ms]
Range (min … max): 856.6 ms … 883.6 ms 10 runs
```
Differential Revision: https://phab.mercurial-scm.org/D9567
mergetools: add new conflict marker format with diffs in
I use 3-way conflict markers. Often when I resolve them, I manually
compare one the base with one side and apply the differences to the
other side. That can be hard when the conflict marker is large. This
patch introduces a new type of conflict marker, which I'm hoping will
make it easier to resolve conflicts.
The new format uses `<<<<<<<` and `>>>>>>>` to open and close the
markers, just like our existing 2-way and 3-way conflict
markers. Instead of having 2 or 3 snapshots (left+right or
left+base+right), it has a sequence of diffs. A diff looks like this:
```
------- base
+++++++ left
a
-b
+c
d
```
A diff that adds one side ("diff from nothing") has a `=======` header
instead and does not have have `+` prefixed on its lines. A regular
3-way merge can be viewed as adding one side plus a diff between the
base and the other side. It thus has two ways of being represented,
depending on which side is being diffed:
```
<<<<<<<
======= left
contents
on
left
------- base
+++++++ right
contents
on
-left
+right
>>>>>>>
```
or
```
<<<<<<<
------- base
+++++++ left
contents
on
-right
+left
======= right
contents
on
right
>>>>>>>
```
I've made it so the new merge tool tries to pick a version that has
the most common lines (no difference in the example above).
I've called the new tool "mergediff" to stick to the convention of
starting with "merge" if the tool tries a regular 3-way merge.
The idea came from my pet VCS (placeholder name `jj`), which has
support for octopus merges and other ways of ending up with merges of
more than 3 versions. I wanted to be able to represent such conflicts
in the working copy and therefore thought of this format (although I
have not yet implemented it in my VCS). I then attended a meeting with
Larry McVoy, who said BitKeeper has an option (`bk smerge -g`) for
showing a similar format, which reminded me to actually attempt this
in Mercurial.
Differential Revision: https://phab.mercurial-scm.org/D9551