Mercurial 2.1.1 - Determine if a changeset is a merge - mercurial

In Mercurial 2.4 a template keyword {p2rev} was added that can be used to determine if a changeset is a merge.
hg log -r42 --template {p2rev}
If this returns "-1", there is no second parent, hence the changeset is not a merge, otherwise it is a merge.
But most devs here still are on Mercurial 2.1.1. Using {p2rev} on their machines always returns [blank].
I tried in 2.1.1:
hg log -r42 --template {parents}
and this gives a bit weird output:
if there is only 1 parent (not a merge): no output
if there are 2 parents (merge): the {rev}:{node} of both parents
What is the best way to determine if a changeset is a merge in Mercurial pre-2.4, say 2.1.1 ?

The hg parents command might do what you want:
hg parents -r 42 --template "{node|short}\n"
For a merge changeset you will get 2 lines of output, and for a non-merge changeset you'll get 1 line.

I am using Mercurial 2.2.2 (Ubuntu 12.10) and it seems that this is working (using the Revision Sets query language):
$ hg log -r 'merge()'
changeset: 6:f75b34694a73
parent: 4:129b7b24f6b4
parent: 5:85771af34f42
[...]
summary: Merge branch 'default' of /foo/proto
changeset: 12:04975792d1f3
parent: 10:42c64107845f
parent: 11:226623b54bd2
[...]
summary: merged branch 'experimental-bar' into 'default'

If
hg log -r"42 & merge()" --template x
returns a non-empty string, Then changeset 42 is a merge.
The template returns the letter x if there is a result.

Related

How to check which branch you are on with mercurial

What is the best way to check which branch I am on with mercurial?
hg log -l 5
This seems to show me the latest commits in the repo and not about working state as git would, so I'm looking for something like git status I suppose, which would tell me what branch I am on. hg status doesn't show me anything.
You can use the hg identify command with the -b for branch option:
C:\Some\Repository> hg identify -b
default
hg branch. I suggest at least reading hg help once :^)
$ hg branch
You can just always use the grep with a keyword to search.
In this case,
$ hg help | grep branch`
Gives you:
branch set or show the current branch name
branches list repository named branches
graft copy changes from other branches onto the current branch
heads show branch heads
You could use hg sum
for example, say you have two branches, A and B
[root#B6LEB1 ATS]# hg update A
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
[root#B6LEB1 ATS]# hg sum
parent: 1787:3f06e1a0260a
made A
branch: A
commit: (clean)
update: (current)
[root#B6LEB1 ATS]# hg update B
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
[root#B6LEB1 ATS]# hg sum
parent: 1788:7ff3c507efd9 tip
made B
branch: B
commit: (clean)
update: (current)
You also might want to specify the currently checked-out version explicitly. Then the output of hg log will return what you look for:
hg log -r.

Mercurial revision checkout is working, but according to the log, the revision is not exist

I have some issue with Mercurial. The checkout of a revision is working (via hg clone -r X command, which clones the X. revision), but when i tried to get log for the X. revision, it returns with revision not exist. How can i solve this problem?
Commands i use:
hg clone -r RevisionNumber /path/to/local/repo my_folder
Then:
hg log -r RevisionNumber --template 'my_template'
hg diff -c RevisionNumber
I get:
abort: unknown revision 'RevisionNumber '!
I tried revisioning with number, and with number:hash, neither worked.
My guess here is that you are referencing the changeset by the revision id (your RevisionNumber) that is local to the original repo. Only the changeset identifying hash is globally unique. I'm basing this guess on your statement
I tried revisioning with number, and with number:hash, neither worked.
You should try using only the hash and see if that works.
hg log -r [hash]
(If you do number:hash, hg thinks your are looking for the range of changes between number and hash.)
Explanation: When you clone to a specific revison, Mercurial only includes changesets that direct ancestors of that revision and leaves out all others. The numbering is locally sequential (meaning new numbers are assigned as the changeset arrives at the repo).

Create a new branch, made a lot of changes, how to view list of files changed?

So there was a new branch created where we made some breaking changes to the codebase.
Now we are going to merge, but before that I want to get a list of all the files that were changed in the branch.
How can I get a list of files? I tried:
hg status --change REV
But i'm not sure if that is what I want, since I want all files changed in this branch and not a specific revision in the branch.
BTW, how can I view the revision numbers?
Try with
$ hg status --rev "branch('your-branch')"
to get the changes between the first and the last changeset on the branch (hg status will implicitly use min(branch('your-branch')) and max(branch('your-branch')) when you give it a range of revisions like this).
Since you'll be merging, you should really look at
$ hg status --rev default:your-branch
to see what is changed between the default branch and your-branch. This shows you the modifications done, and filters out any modifications done on the branch due to merges with default.
This is necessary in case your history looks like this:
your-branch: x --- o --- o --- o --- o --- o --- y
/ / /
default: o --- a --- o --- b --- o --- c --- o --- o --- d
where you've already merged default into your branch a couple of times. Merging default into your branch is normal since you want to regularly integrate the latest stuff from that branch to avoid the branches drifting too far away from each other.
But if a new file was introduced on default and later merged up into B, then you don't really want to see that in the hg status output. You will see it if you do
$ hg status --rev a:y
since the file was not present in a, but is present in y. If you do
$ hg status --rev d:y
then you wont see the file in the output, assuming that it's present in both heads.
You write in a comment that you're working Kiln repository. They mean "clone" when they say "branch", but the above can still be adapted for your case. All changesets will be on the default named branch, but that's okay.
Run the following command in your local clone of the "branch" repository:
$ hg bookmark -r tip mybranch
This marks the current tip as the head of mybranch. Then pull all the changesets from the main repository:
$ hg pull https://you.kilnhg.com/Repo/public/Group/Main
You then mark the new tip as the tip of the main repository:
$ hg bookmark -r tip main
You can now run
$ hg status --rev main:mybranch
to see the changes between main and my-branch. If you want to see what you did on the branch itself, the use
$ hg status --rev "::mybranch - ::main"
The ::mybranch part will select changesets that are ancestors of mybranch — this is all your new work, plus old history from before you branched. We remove the old history with - ::main. In older versions of Mercurial, you would use hg log -r -r mybranch:0 -P main.
In cases like this, I prefer to do a test merge from a newly checked-out copy of the repo. This has the advantage that I can see how many conflicts the merge will produce, and I can keep the merge result because I did it in its own copy.
To view the revision numbers, enable the graphlog extension and run:
$ hg log -b your-branch -G
This gives you a nice ASCII graph. This can be handy to quickly look at the graph, but I recommend using TortoiseHg for a cross-platform log viewer:
I had to merge the default branch into my branch to get some fixes, now the commands above shows also files changed because of merges (this files changed after the merge again in the default branch).
Therefore, to get only the correct files I use something like this:
hg log --rev "branch('my-branch') and not merge()" --template '{files}\n' | sed -e 's/ /\n/g' | sort -u
if you have spaces in file names, you can do it this way:
hg log --rev "branch('my-branch') and not merge()" --template '{rev}\0' | xargs -0 -I # hg status -n --change # | sort -u
And to answer your last question, revisions can be shown this way:
hg log --rev "branch('my-branch') and not merge()" --template '{rev}\n'
TIP: I use a hg-alias for this:
[alias]
_lf = ! $HG log --rev "branch(\"$1\") and not merge()" --template '{rev}\0' | xargs -0 -I # hg status -n --change # | sort -u
With mercurial, if you want to get the list of all the files changed in your current branch (changes done of your changeset) you can use these commands: :
hg log --branch $(hg branch) --stat | grep '|' | awk -F\ '{printf ("%s\n", $1)}' | sort -u
Example result:
api/tests/test_my_app.py
docker/run.sh
api/my_app.py
Explanation of the commands:
hg log --branch $(hg branch) --stat
Show revision history of entire repository or files and output diffstat-style summary of changes
hg branch
Show the current branch name
grep '|'
Search for a text pattern, in this case, it is "|"
awk -F\ '{printf ("%s\n", $1)}'
Space separator denotes each field in a record and prints each one in a new line
sort -u
Sort all the printed lines and delete duplicates

Mark changes as already merged or deliberately ignored with hg pull/push/merge/graft?

I'm transitioning to Mercurial from Subversion, where I'm used to using svnmerge.py to track changes that have already been merged, or which have been blocked from being merged:
# Mark change 123 as having already been merged; it will not be merged again, even if a range
# that contains it is subsequently specified.
svnmerge.py merge -M -r123
#
# Block change 326 from being considered for merges.
svnmerge.py merge -X -r326
#
# Show changes that are available for merging from the source branch.
svnmerge.py avail
#
# Do a catchall merge of the remaining changes. Neither change 123 nor change 326 will be
# considered for merging.
svnmerge.py merge
I want to be able to do something similar for hg pull/push/merge/graft, so that if I know that I never want to merge a given change, I can just block it from consideration, making subsequent cherry-picking, merging, etc., into a more fire-and-forget affair. I have done a lot of googling, but have not found a way to do this.
There also appears to be no way to view a list of as-yet-ungrafted changes.
As I'm often tidying up after other developers and helping them with their merges, it's immensely helpful to be able to do these kinds of things, which one might well consider "inverse cherry-picking;" i.e., marking changes that you do NOT want to merge, and then doing a bulk merge of the remainder.
DAG-based systems like Mercurial ans Git are all or nothing: when you merge two branches, you do a three-way merge of the common ancestor and the two branches.
The three-way merge is only concerned with the final stage of each branch. For instance, it doesn't matter if you make your changes in 10 it 1000 steps — the merge result will be the same.
This implies that the only way to ignore a changeset is to back it out before the merge:
$ hg backout BAD
That will cancel the changeset on the branch, making it appear that it was never made from the perspective of the three-way merge.
If you have a whole branch that you want to merge, but ignore, then you can do a dummy merge:
$ hg merge --tool internal:local --non-interactive
$ hg revert --all --rev .
That goes through the merge, but reverts back to the old state before committing.
The best advice I can give you is to structure your workflow so that the above backouts aren't necessary. This means committing a bugfix on the oldest applicative branch. If a bug is found while creating feature X, then use hg bisect to figure out when the bug was introduced. Now updated back to the oldest branch where you still want to fix the bug:
$ hg update 2.0
# fix bug
$ hg commit -m "Fixed issue-123"
then merge the bugfix into all later branches:
$ hg update 2.1
$ hg merge 2.0
$ hg commit -m "Merge with 2.0 to get bugfix for issue-123"
$ hg update 2.2
$ hg merge 2.1
$ hg commit -m "Merge with 2.1 to get bugfix for issue-123"
If the bugfix no longer applies, then you should still merge, but throw away the unrelated changes:
$ hg update 3.0
$ hg merge 2.2 --tool internal:local --non-interactive
$ hg revert --all --rev .
$ hg commit -m "Dummy merge with 2.2"
That ensures that you can always use
$ hg log -r "::2.2 - ::3.0"
to see changesets on the 2.2 branch that haven't been merged into 3.0 yet.

Mercurial - see list of files that need to be manually merged?

Is there a Mercurial command you can use after an hg pull to see a list of all files that will be need to be manually merged (ie: that have conflicts) when doing an hg merge?
hg resolve --list
From the documentation:
Merges with unresolved conflicts are often the result of non-interactive merging using the internal:merge configuration setting, or a command-line merge tool like diff3. The resolve command is used to manage the files involved in a merge, after hg merge has been run, and before hg commit is run (i.e. the working directory must have two parents).
Edit 5 January 2012:
(I received an up vote for this answer today so I revisited it. I discovered that I misunderstood the question.)
The question is "I have performed a pull from a remote repository and have not yet performed a merge. Can I see what conflicts will be created upon performing the merge?"
My answer above is clearly wrong. After reading through the linked documentation, I do not think there is a built-in method for doing this. However, there is a way to do it without ruining your working source tree.
Let's assume you have cloned repository A from some remote source to repository B on your local system, i.e. hg clone http://hg.example.com/A B. After doing so, you make changes to your local repository, B, that involve at least one commit. In the meantime, changes have been made to repository A so that when you do a pull you get a message indicated new changesets have been added and heads have been created.
At this point, you can do hg heads to list the two changesets that will be involved in a merge. From this information, you can issue a status command to list the differences between the heads. Assuming the revision numbers in your repository B, according to the heads list, are "1" and "2", then you can do hg status --rev 1:2 to see a list of the changes.
Of course, this doesn't really tell you if conflicts will occur when you do a merge. Since there isn't a command that will show you this, you will have to "preview" the merge by cloning to a new repository and doing the merge there. So, hg clone B C && cd C && hg merge. If you are satisfied with the result of this merge you can do hg com -m 'Merging complete' && hg push && cd ../ && rm -rf C.
It's a bit of a process, but it keeps your current source tree clean if the merge turns out to be a disaster. You might also find this description of working with public repositories helpful.
Unless I'm misreading it myself, the answers above don't seem to address the question that I think is being asked: I have two branches in my repository that I'd like to merge, and I want to know what conflicts will come up (e.g., before stepping through the conflict resolutions one-by-one.)
To do this, I would merge with the :merge3 tool (which tries to merge automatically, but leaves conflicts unresolved) and then use hg resolve --list — or just look at the output of merge command — to see the conflicts.
hg merge <otherbranch> --tool :merge3
hg resolve -l
If you didn't actually want to merge in the end (if you just want to see what would conflict) you can run hg update -C afterwards to undo the merge.
If you do want to finish the merge, you can run hg resolve <filepath> for each file, or just hg resolve --all to step through all that remain with conflicts, before you hg commit the merge changeset.
You can use the --rev option of hg stat with a pair of revisions to see what file differences exist between the two. See below for a slightly verbose but detailed example:
First we start by making a new repository:
[gkeramidas /tmp]$ hg init foo
[gkeramidas /tmp]$ cd foo
Then add a single file called foo.txt to the new repository:
[gkeramidas /tmp/foo]$ echo foo > foo.txt
[gkeramidas /tmp/foo]$ hg commit -Am 'add foo'
adding foo.txt
[gkeramidas /tmp/foo]$ hg glog
# 0[tip] b7ac7bd864b7 2011-01-30 18:11 -0800 gkeramidas
add foo
Now add a second file, called bar.txt as revision 1:
[gkeramidas /tmp/foo]$ echo bar > bar.txt
[gkeramidas /tmp/foo]$ hg commit -Am 'add bar'
adding bar.txt
Go back to revision 0, and add a third file, on a different head. This is done to simulate a pull from someone else who had cloned the same repository at its starting revision:
[gkeramidas /tmp/foo]$ hg up -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
[gkeramidas /tmp/foo]$ echo koko > koko.txt
[gkeramidas /tmp/foo]$ hg commit -Am 'add koko'
adding koko.txt
created new head
[gkeramidas /tmp/foo]$ hg glog
# 2[tip]:0 e5d80abdcb06 2011-01-30 18:12 -0800 gkeramidas
| add koko
|
| o 1 a2d0d0e66ce4 2011-01-30 18:12 -0800 gkeramidas
|/ add bar
|
o 0 b7ac7bd864b7 2011-01-30 18:11 -0800 gkeramidas
add foo
Now you can use hg stat to see what file differences exist between any pair of revisions, e.g. the changes from rev 0 to rev 1 added 'bar.txt' to the file list:
[gkeramidas /tmp/foo]$ hg stat --rev 0:1
A bar.txt
The changes from rev 0 to rev2 added 'koko.txt' to the file list:
[gkeramidas /tmp/foo]$ hg stat --rev 0:2
A koko.txt
But more interestingly, the changes from rev 1 to rev 2 involve two file manifest changes. (1) 'koko.txt' was added in rev 2, and (2) 'bar.txt' exists in rev 1 but is missing from rev 2, so it shows as a 'removed' file:
[gkeramidas /tmp/foo]$ hg stat --rev 1:2
A koko.txt
R bar.txt
I think hg status is what you are looking for.
You may want to read this chapter from Mercurial: The Definitive Guide
http://hgbook.red-bean.com/read/mercurial-in-daily-use.html