hg reverse diff of a single revision - mercurial

If doing hg diff --rev 1 --rev 2, one can get the reverse diff by swapping the order of the --rev arguments. Is there a way to do this more generally, including when using the -c argument, or when taking the diff of the working directory?

Excerpt from the man page of hg diff:
--reverse produce a diff that undoes the changes
So simply employ that flag in addition to whatever flags you need to create the diff you are interested in

Related

How can I view the remaining changesets left to check in an hg bisect?

When I'm running hg bisect, sometimes I want to "look ahead" at what's remaining, to see if there are any obvious culprits I could check while a fairly slow bisection test runs.
So given I've run
> hg bisect -g
Testing changeset 15802:446defa0e64a (8 changesets remaining, ~2 tests)
How can I view which 8 changesets are remaining?
You can use the bisect("untested") revset to view the untested changesets. E.g.:
hg log -r 'bisect(untested)'
If that is too much information, you can also combine it with a template option:
hg log -r 'bisect(untested)' -T '{rev}\n'
Or you can just restrict the output to the first and last entry of the range:
hg log -r 'first(bisect(untested))+last(bisect(untested))'
You can also create revset aliases in your .hg/hgrc or ~/.hgrc file to save some typing, e.g.:
[revsetalias]
tbt = bisect("untested")
tbt2 = first(tbt)+last(tbt)
Then you can do (for example):
hg log -r tbt
Note that if you call a revset alias untested, you'll have to quote the string untested (e.g. bisect("untested")), hence my choice of tbt (for "to be tested").
See hg help revsets for more revsets pertaining to bisection.

Diff after committing locally

I just cloned a repo from their remote.
I built the software, changed about 4 files, committed them locally and now want to create a patch that I can show them.
When I run :
hg diff -U8p abc efg pqr > patch_file
I don't see the changes I made. Does hg diff only compare the current files with the last committed files?
How do I get this to work?
To diff the working directory against a particular revision REV, use
hg diff -r REV
To compare two revisions against each other, use
hg diff -r REV1 -r REV2
To figure out which revisions to compare, examine the output of hg log. If you'll be doing this a lot and the base revision is fixed, give it a name (e.g., whatipulled) with
hg tag -r REV whatipulled
You can then specify whatipulled as the revision, instead of a numeric rev id (or a hash).
To export your diffs in a richer format, including commit comments etc., you can also use the following which is designed for this purpose:
hg export -r REV
There's also hg bundle -r REV, which produces a binary file with similar information.
But if you're sending changes back to the parent repo, the best method is to use hg push. It communicates your changesets directly to the parent; you don't even need to know which changesets need pushing. Of course, you must have the right to push to the parent repo.
hg push [ parent_repo_url ]
(If you pulled from it, mercurial should already know the path and you can leave it out).
If the parent repo is on bitbucket and you don't have pu, you can set up your own account on bitbucket, pull/push to that from your local repo, and then issue a "pull request" to the project repo, asking them to pull from you.
All of the above have options to control their behavior, which see.
From hg help diff
If only one revision is specified then that revision is compared to the working directory
In your diff for -r you must to use old tip (latest "not your" changeset) and update to tip (your latest changeset) before diffing.
If some binary data was modified in your changesets, don't forget to use -g option
hg up & hg diff -r <CSET> -g > some.patch
Improved diff for any active changeset and without hand-work for detecting base changeset (for linear history == in single branch)
hg diff -r "parent(min(outgoing()))" -r tip
By default, hg diff compares the currently checked out file with the last commit. You can change this by adding options:
-r REV compares the currently checked out files with a specific revision REV.
-c REV shows the changes made by revision REV
So in your case hg diff -c 123 ... would give you the diff for commit 123.
My guess is that hg outgoing is exactly what you want -- it compares what you've committed locally with what is at the default remote server and shows you a list of those changesets or with -p the commits.
That does, however, shows each changeset separately. If you want to see all the changes combined, you'd have to do hg diff -r HERE -r THERE or since -r HERE is a default, hg diff -r THERE
I see you've asked in a comment "How do I know what THERE is", where THERE is the last changeset remote has, and you can get that answer by doing hg outgoing. If hg outgoing shows it would send changesets 66, 67, and 68, then you want to do hg diff -r 65 to compare what's already there (65) with what's local (68).

Mercurial: Easy way to see changes from last commit

In Mercurial, I can see my current (uncommitted) changes by running
$ hg diff
Fine. But after commit, I sometimes want to see this diff again (i.e., the diff of the last changeset). I know I can achieve this by
$ hg log -l 1
changeset: 1234
tag ...
$ hg diff -c 1234
I'm looking for a way to do this in one line.
Use hg diff -c tip, or hg tip -p (shorter, but works only for tip).
This will work until you pull something, since tip is an alias for the most recent revision to appear in the repo, either by local commit or
pull/push from remote repositories.
You can use relative revision numbers for the --change option:
hg diff -c -1
See https://stackoverflow.com/a/3547662/239247 for more info.
An alternative is to use: hg diff --rev -2:-1
This form has the advantage that it can be used with the status command (e.g. hg st --rev -2:-1), and using it makes it easy to remember what to do when one needs to determine differences between other revision pairs (e.g. hg diff --rev 0:tip).
The answer from Macke is quite helpful, but in my case I didn't want to diff tip.
Thankfully you can also just diff the currently selected comment:
hg diff -c .

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

Is there any way to see difference between last two versions of a file using hg commands?

I want something like this
hg vdiff filename.txt -lastRevision -secondLastRevision
I don't know what vdiff is, but how about:
hg diff -r rev1 -r rev2 filename.txt
Edit: to get the last 2 revisions, that would be:
hg diff -r -2 -r -1 filename.txt
Type hg help revisions for information about specifying revisions.
As of this writing, the top answers refer to -1, -2 and -3. The negative integers are historical artifacts and should not be used with modern Mercurial workflows.
Typically, the "last version" means "the currently checked out revision". In that case, to see the changes to file in the currently checked out commit, you can use
hg diff --change . filename.txt
If you'd like to see the last time filename.txt was changed, you can use
hg log --follow --patch --limit 1 filename.txt
The --follow argument causes hg log to follow history, so it'll only output the current revision or its ancestors.
Use
hg diff -r -3 -r -2 file