When updating to a new revision, check for path conflicts caused by unknown
files in the working directory, and handle these by backing up the file or
directory and replacing it.
Differential Revision: https://phab.mercurial-scm.org/D781
This is a fix to an old problem when Mercurial got confused by an
untracked folder with the same name as one of the files in a commit
hg was trying to update to. It is pretty safe to remove this folder if
it is empty. Backing up an empty folder seems to go against Mercurial's
"don't track dirs" philosophy.
In some real-world cases it is preferable to allow overwriting ignored files
while continuing to abort on unknown files. This primarily happens when we're
replacing build artifacts (which are ignored) with checked in files, but
continuing to abort on differing files that aren't ignored.
We're redefining merge.checkunknown to only control the behavior for files
that aren't ignored. That's fine because this config was only very recently
introduced and has not made its way into any Mercurial releases yet.
A 'colliding unknown file' is a file that meets all of the following
conditions:
- is untracked or ignored on disk
- is present in the changeset being merged or updated to
- has different contents
Previously, we would always abort whenever we saw such files. With this config
option we can choose to warn and back the unknown files up instead, or even
forgo the warning entirely and silently back the unknown files up.
Common use cases for this configuration include a large scale transition of
formerly ignored unknown files to tracked files. In some cases the files can be
given new names, but in other cases, external "convention over configuration"
constraints have determined that the file must retain the same name as before.
Previously, we were using Python's native 'os.path.isfile' method which follows
symlinks. In this case, since we're operating on repo contents, we don't want
to follow symlinks.
There's a behaviour change here, as shown by the second part of the added test.
Consider a symlink 'f' pointing to a file containing 'abc'. If we try and
replace it with a file with contents 'abc', previously we would have let it
though. Now we don't. Although this breaks naive inspection with tools like
'cat' and 'diff', on balance I believe this is the right change.
The home of 'Abort' is 'error' not 'util' however, a lot of code seems to be
confused about that and gives all the credit to 'util' instead of the
hardworking 'error'. In a spirit of equity, we break the cycle of injustice and
give back to 'error' the respect it deserves. And screw that 'util' poser.
For great justice.
To detect change of a file without redundant comparison of file
content, dirstate recognizes a file as certainly clean, if:
(1) it is already known as "normal",
(2) dirstate entry for it has valid (= not "-1") timestamp, and
(3) mode, size and timestamp of it on the filesystem are as same as
ones expected in dirstate
This works as expected in many cases, but doesn't in the corner case
that changing a file keeps mode, size and timestamp of it on the
filesystem.
The timetable below shows steps in one of typical such situations:
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
N -1 ***
- make file "f" clean N
- execute 'hg foobar'
- instantiate 'dirstate' -1 -1
- 'dirstate.normal("f")' N -1
(e.g. via dirty check)
- change "f", but keep size N
N+1
- release wlock
- 'dirstate.write()' N N
- 'hg status' shows "f" as "clean" N N N
---- ----------------------------------- ---- ----- -----
The most important point is that 'dirstate.write()' is executed at N+1
or later. This causes writing dirstate timestamp N of "f" out
successfully. If it is executed at N, 'parsers.pack_dirstate()'
replaces timestamp N with "-1" before actual writing dirstate out.
Occasional test failure for unexpected file status is typical example
of this corner case. Batch execution with small working directory is
finished in no time, and rarely satisfies condition (2) above.
This issue can occur in cases below;
- 'hg revert --rev REV' for revisions other than the parent
- failure of 'merge.update()' before 'merge.recordupdates()'
The root cause of this issue is that files are changed without
flushing in-memory dirstate changes via 'repo.commit()' (even though
omitting 'dirstate.normallookup()' on changed files also causes this
issue).
To detect changes of files correctly, this patch writes in-memory
dirstate changes out explicitly after marking files as clean in
'workingctx._checklookup()', which is invoked via 'repo.status()'.
After this change, timetable is changed as below:
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
N -1 ***
- make file "f" clean N
- execute 'hg foobar'
- instantiate 'dirstate' -1 -1
- 'dirstate.normal("f")' N -1
(e.g. via dirty check)
----------------------------------- ---- ----- -----
- 'dirsttate.write()' -1 -1
----------------------------------- ---- ----- -----
- change "f", but keep size N
N+1
- release wlock
- 'dirstate.write()' -1 -1
- 'hg status' -1 -1 N
---- ----------------------------------- ---- ----- -----
To reproduce this issue in tests certainly, this patch emulates some
timing critical actions as below:
- timestamp of "f" in '.hg/dirstate' is -1 at the beginning
'hg debugrebuildstate' before command invocation ensures it.
- make file "f" clean at N
- change "f" at N
'touch -t 200001010000' before and after command invocation
changes mtime of "f" to "2000-01-01 00:00" (= N).
- invoke 'dirstate.write()' via 'repo.status()' at N
'fakedirstatewritetime.py' forces 'pack_dirstate()' to use
"2000-01-01 00:00" as "now", only if 'pack_dirstate()' is invoked
via 'workingctx._checklookup()'.
- invoke 'dirstate.write()' via releasing wlock at N+1 (or "not at N")
'pack_dirstate()' via releasing wlock uses actual timestamp at
runtime as "now", and it should be different from the "2000-01-01
00:00" of "f".
BTW, this patch also changes 'test-largefiles-misc.t', because adding
'dirstate.write()' makes recent dirstate changes visible to external
process.
The phase of the pending commit depends on the parent of the working directory
and on the phases.newcommit configuration.
First, this information rather depend on the commit line which describe the
pending commit.
Then, we only want to be advertised when the pending phase is going to be higher
than the default new commit phase.
So the format will change from
$ hg summary
parent: 2:ab91dfabc5ad
foo
parent: 3:24f1031ad244 tip
bar
branch: default
commit: 1 modified, 1 unknown, 1 unresolved (merge)
update: (current)
phases: 1 secret (secret)
to
parent: 2:ab91dfabc5ad
foo
parent: 3:24f1031ad244 tip
bar
branch: default
commit: 1 modified, 1 unknown, 1 unresolved (merge) (secret)
update: (current)
phases: 1 secret
The number of draft and secret changesets are currently not summarized.
This is an important information because the number of drafts give some rough
idea of the number of outgoing changesets in typical workflows, without needing
to probe a remote repository. And a non-zero number of secrets means that
those changeset will not be pushed.
If the repository is "dirty" - some draft or secret changesets exists - then
summary will display a line like:
phases: X draft, Y secret (public)
The phase in parenthesis corresponds to the highest phase of the parents of
the working directory, i.e. the current phase.
By default, the line is not printed if the repository is "clean" - all
changesets are public - but if verbose is activated, it will display:
phases: (public)
On the other hand, nothing will be printed if quiet is in action.
A few tests have been added in test-phases.t to cover the -v and -q cases.
Many tests didn't change back from subdirectories at the end of the tests ...
and they don't have to. The missing 'cd ..' could always be added when another
test case is added to the test file.
This change do that tests (99.5%) consistently end up in $TESTDIR where they
started, thus making it simpler to extend them or move them around.
When doing hg up, if there is a file conflict with untracked files,
currently only the first such conflict is reported. With this patch,
all of them are listed.
With this patch error message is now reported as
a: untracked file differs
b: untracked file differs
abort: untracked files in working directory conflict with files in
requested revision
instead of
abort: untracked file in working directory differs from file in
requested revision: 'a'
This is a follow up to an old attempt to do this here:
http://selenic.com/pipermail/mercurial-devel/2011-August/033625.html
Makes the 'nothing to merge' abort messages in commands.py consistent with
those in merge.py. Also makes commands.merge() and merge.update() use hints.
The tests show the changes.
Many tests fixed the commit date of their changesets at '1000000 0' or
similar. However testing with "Mon Jan 12 13:46:40 1970 +0000" is not
better than testing with "Thu Jan 01 00:00:00 1970 +0000", which is
the default run-tests.py installs.
Removing the unnecessary flag removes some clutter and will hopefully
make it clearer what the tests are really trying to test. Some tests
did not even change their output when the dates were changed, in which
case the -d flag was truly irrelevant.
Dates used in sequence (such as '0 0', '1 0', etc...) were left alone
since they may make the test easier to understand.
