commit: improve the files field of changelog for merges
Currently, the files list of merge commits repeats all the deletions
(either actual deletions, or files that got renamed) that happened
between base and p2 of the merge. If p2 is the main branch, the list
can easily be much bigger than the change being merged.
This results in various problems worth improving:
- changelog is bigger than necessary
- `hg log directory` lists many unrelated merge commits, and `hg log
-v -r commit` frequently fills multiple screens worth of files
- it possibly slows down adjustlinkrev, by forcing it to read more
manifests, and that function can certainly be a bottleneck
- the server side of pulls can waste a lot of time simply opening the
filelogs for pointless files (the constant factors for opening even
a tiny filelog is apparently pretty bad)
So stop listing such files as described in the code. Impacted merge
commits and their descendants get a different hash than they would
have without this. This doesn't seem problematic, except for
convert. The previous commit helped with that in the hg->hg case (but
if you do svn->hg twice from scratch, hashes can still change).
The rest of the description is numbers. I don't have much to report,
because recreating the files list of existing repositories is not
easy:
- debugupgradeformat and bundle/unbundle don't recreate the list
- export/import tends to choke quickly applying patches or on
description that contain diffs,
- merge commits from the convert extension don't have the right files
list for reasons orthogonal to the current commit
- replaying the merge with hg update/hg merge/hg revert --all/hg
commit can end up failing in hg revert
- I wasn't sure that using debugsetparents + debugrebuilddirstate
would really build the right thing
I measured commit time before and after this change, in a case with no
files filtered out, several files filtered out (no difference) and 5k
files filtered out (+1% time).
Recreating the 100 more recent merges in a private repo, the
concatenated uncompressed files lists goes from 1.12MB to
0.52MB. Excluding 3 merges that are not representative, then the size
goes from 570k to 15k.
I converted part of mozilla-central, and observed file list shrinking
quite a bit too, starting at the very first merge,
733641d9feaf, going
from 550 files to 10 files (although they have relatively few merges,
so they probably wouldn't care).
Differential Revision: https://phab.mercurial-scm.org/D6613
== New Features ==
* New config `commands.commit.post-status` shows status after successful
commit.
* `hg root` now has templating support, including support for showing
where a repo share's source is. See `hg help -v root` for details.
* New `--force-close-branch` flag for `hg commit` to forcibly close
branch from a non-head changeset.
* The curses-based interface for commands like `hg commit -i` now supports
a range-select mechanism. Select the first line using space like before,
navigate to the last line, and press X (capital x) to set all items in
the range at once. Lowercase x has been added as a synonym for space to
help reinforce the mechanism, and pressing enter/return continues to be a
synonym for "toggle the current line and move down to the next item in
this section."
== New Experimental Features ==
* New config `experimental.log.topo` makes `hg log -G` use
topological sorting. This is especially useful for aliases since it
lets the alias accept an `-r` option while still using topological
sorting with or without the `-r` (unlike if you use the `sort(...,
topo)` revset).
== Bug Fixes ==
* issue4292: "hg log and {files} {file_adds} {file_mods} {file_dels}
in template show wrong files on merged revision". See details in
"Backwards Compatibility Changes".
== Backwards Compatibility Changes ==
* Removed (experimental) support for log graph lines mixing
parent/grandparent styles. Setting
e.g. `experimental.graphstyle.parent = !` and
`experimental.graphstyle.grandparent = 3.` would use `!` for the
first three lines of the graph and then `.`. This is no longer
supported.
* If `ui.origbackuppath` had been (incorrectly) configured to point
to a file, we will now replace that file by a directory and put
backups in that directory. This is similar to how we would
previously replace files *in* the configured directory by
subdirectories.
* Template keyword `{file_mods}`, `{file_adds}`, and `{file_dels}`
have changed behavior on merge commits. They used to be relative to
the first parent, but they now consider both parents. `{file_adds}`
shows files that exists in the commit but did not exist in either
parent. `{file_dels}` shows files that do not exist in the commit
but existed in either parent. `{file_mods}` show the remaining
files from `{files}` that were not in the other two
sets.
== Internal API Changes ==
* Matchers are no longer iterable. Use `match.files()` instead.
* `match.visitdir()` and `match.visitchildrenset()` now expect the
empty string instead of '.' to indicate the root directory.
* `util.dirs()` and `util.finddirs()` now include an entry for the
root directory (empty string).
* shelve is no longer an extension now. it will be turned on by default.
* New API to manage unfinished operations: Earlier there were distinct APIs
which dealt with unfinished states and separate lists maintaining them
that are `cmdutil.afterresolvestates`, `cmdutil.unfinishedstates` and
`cmdutil.STATES`. Now these have been unified to a single
API which handles the various states and their utilities. This API
has been added to `state.py`. Now instead of adding to these 3 lists
independently a state for a new operation can be registered using
`addunfinished()` in `state` module.
* `cmdutil.checkunfinished()` now includes detection for merge too.
* merge abort has been disallowed in case an operation of higher
precedence is in progress to avoid cases of partial abort of
operations.
* We used to automatically attempt to make extensions compatible with
Python 3 (by translating their source code while loading it). We no
longer do that.