How do I rename a branch specification in perforce? - perforce

I would like to know how to rename a branch specification (aka, a "branch mapping") in perforce. The P4V client does not allow you to edit the branch spec name.
Is it safe to just add another branch specification, copy the settings and remove the old one?

Perforce does not provide a mechanism to rename a branch specification. Perhaps they fear you may inadvertently break some scripts if you go and rename one?
Yes, it is safe to create a new one, copy the settings from the old and delete it (provided nothing is relying on a branch specification with that old name, of course).

Lack of branch spec renaming extends to all specs (users, groups, clients, labels, jobs, etc.). This is where the command line can come in handy:
p4 branch -o OLDBRANCH | sed -e "s,OLDBRANCH,NEWBRANCH," | p4 branch -i && p4 branch -d OLDBRANCH

Check this link:
http://kb.perforce.com/article/24/renaming-depot-directories
The procedure depends on your server version. For example in the 2009+ servers you use pedit and pmove to rename and keep your file history.

Yes. But you need to do an p4 integrate to get the files over. That is what p4v "copy or rename" does. Use the rename option, that also deletes the old files.

Related

How to branch in perforce

I'm a software engineer that uses git professionally but haven't tried using perforce until today. I searched about branch in perforce but I noticed that most of the informations that I found were all made by just using the branch in GUI then it creates a new folder (ie. /depot/MAIN/ to /depot/DEV/)
Is this how it works? What's the standards in naming the branches? Is it all caps?
Thanks
Branch names do not have to be in upper case only.
To create a new branch you can use the 'p4 integrate' command.
You can also use 'p4 copy' or 'p4 populate', depending on whether you want to exactly copy the source, or do the branch and submit in one action.
More information about branching is located here:
https://www.perforce.com/perforce//manuals/p4guide/chapter.codelines.html
If you're used to git branches you might like Perforce streams and the p4 switch command, which works a lot like git branch. For example:
p4 switch -c dev
stashes your current work, creates a new branch called dev based on your current branch, and switches to it. To bring your current work into the new branch, add the -r flag.
At its core streams really use the same concepts as "classic" (unmanaged) inter-file branching, and there are things you can do with Perforce's branching model that you can't with git's, but if you want something that feels more or less like git the switch command abstracts away a lot of the commands you'd have to learn otherwise.

Is it possible to create a patch using a set of changelists?

Problem: 2 projects shared trunk and were updating some of the same files. Now one project needs to be released, so a new branch was created from a checkpoint before the projects started.
I have a list of just my changelist numbers from the mainline. Using that I can generate a list changed files and diff output using a script with a series of 'p4 describe #' commands.
Can I reformat that output and apply it to the new branch somehow?
Response to the title: "Is it possible to create a patch using a set of changelists?"
Yes.
p4 diff2 -u //path_to_your_sources/...#cln_minus_1 //path_to_your_sources/...#cln > /tmp/cln.patch.
You can then use /tmp/cln.patch as input to the patch utility. Here, 'cln' is the submitted change list number that you want to create a patch for.
I've just spent two hours struggling with this. Using cygwin patch, I had to munge the paths until they were recognised.
In the end, the magic incantation looked like this (broken across lines):
p4 diff2 -u //depot/foo/main/...#100003 //depot/foo/main/...#100000 |
sed 's#//depot/#E:/Source/#g' |
sed '/^+++\|---/s#/#\\#g' |
patch
That is:
Use p4 diff2 to get a unified diff (-u) of part of the depot between the two revisions that I care about. The second changelist is the one before the first one I want, otherwise it's not included in the diff.
Use sed to change the //depot/ to E:/Source/, which is where my workspace lives.
Change forward slashes to double backslashes (this seems to make it work).
Pipe the results through patch.
Cygwin patch is smart enough to check files out of Perforce, but I'm not sure how to get it to do it silently. It prompts with Get file 'e:\Source\foo\whatever' from Perforce with lock?.
This is with p4 version 2010.1, a fairly recent installation of Cygwin, running on PowerShell.
Oh, and after this, patch wrote out Unix-style line endings, so I used u2d to fix those up.
Perforce will let you cherry-pick changelists for integration, which may be easier than trying to generate and apply a patch. Perforce will keep track of what revisions you've integrated where, which may make future integrations easier.
Let's assume you used to have one trunk:
//depot/mycode/trunk
And you checked in all of your changes there. You branched trunk at some point in the past to:
//depot/mycode/rel
And you have a list of changelists on trunk to merge. From a client spec that maps rel, integrate each changelist:
p4 integrate //depot/mycode/trunk/...#1234,1234 //depot/mycode/rel/...
where 1234 is the changelist number. Resolve after each integration. You may also wish to build, test, and commit your integrations at various checkpoints during your integration, if you can identify good points to do so. (Perforce can handle multiple integrations per commit, but if you make a mistake you'll need to revert to the last version checked in and redo the intermediate integrations and resolves.)
p4 describe -S -du <CL number>
is the shorter and most concise command, in my opinion.

perforce: create a local backup of current pendinglist

in perforce, i have a pending list with some changed files. now i want to revert to the base, but without loosing my changes, so i want to back them up somewhere. like saving the DIFFs of each file. at a later time, i want to restore those changes and continue my work.
is this possible? if so, how?
thanks!
there is no need for external tools at all, assuming you are on a unix machine (or have a proper cygwin setup under Windows, haven't tested it.) The only caveat is that Perforce's p4 diff produces an output that is slightly incompatible with patch, therefore you need it to point to your unix diff-command. In your client-root you can do
P4DIFF=/usr/bin/diff p4 diff -du > pending-changes.patch
optional (if you want to revert the open files from the command-line, otherwise use p4v):
p4 revert `p4 opened|awk -F\# '{print $1}'`
Later you would open the files for edit (can be automated by extracting the affected files from the patchfile pending-changes.patch and then:
patch < pending-patches
Depending on your path-layout in your client-root, you have to use the -p#num option of patch to get the patch applied cleanly.
You should be able to do a shelve. It's a way of saving a changelist for future editing. The link below is a Python add-in for Perforce that implements shelve. Also, I know that Practical Perforce has a couple of ways to shelve current changes without an external script. I don't have the book in front of me but I'll try to update this question tonight when I do.
http://public.perforce.com/wiki/P4_Shelve
Linked to from P4Shelve, is P4tar which looks very useful, and does the operations on the client, rather than branching on the server.
Certainly I'll be looking into doing similar things soon.
See also this question:
Sending my changelist to someone else without checking in.
It's basically the same thing.
Create a branch of these files in some appropriate location
Check out the branch versions of the files you have edited
Copy the edited files over from the trunk and submit them
Revert the files on the trunk
Now you've got those "diffs" you wanted safely archived. When your ready to apply those changes later on, just integrate them back into the trunk.
This is what the Python script, that Brett mentioned, does. This is the way to do it manually without any special tools.

How to create a duplicate changelist in Perforce during integration across branches?

Is there a way to duplicate the change list description using p4 command line when integrating from the source change list across branches ?
Details:
For e.g.
p4 integ -t -b branch_a_to_branch_b -s //my/tree/...#2425,#2425
integrates files from changelist 2425 to the default changelist in the target branch branch_b from source branch branch_a
Is it possible to create a new changelist which has the same description as the source changelist ?
Then the target integration can be done on this new changelist.
I don't know of a way to do this in one command, but it seems like it would be easy enough to script up. You might want to look at the commands p4v runs when it integrates, as it has the option to integrate to a new changelist. Then it would simply be a matter of changing the description of the new changelist to match the old one.

Can I integrate checked out files into a different branch on perforce

We were working on a design, and for that we created the skeleton of the classes in our main branch. Now, we are starting to code, and for that we got a new branch. So, it would be nice if I can move all the new files in the main branch into the new branch. However, I cannot check them in yet. So, is it possible to integrate the checked out changelist? Thanks.
The Perforce support web site explains how to do this: Perforce Knowledge Base: Branching work in progress. It would be nicer if it was a single step that didn't require running eight different commands.
Since release 2013.1, the way to branch work in progress is to shelve the work and unshelve it on the branch. In detail:
Shelve your outstanding changes:
$ p4 shelve ...
Change 182535 created with 10 open file(s).
Shelving files for change 182535.
edit //info.ravenbrook.com/project/mps/master/code/arenavm.c#26
# etc.
Unshelve them on the branch (using the -b option, which maps the file name through a branch specification):
$ p4 unshelve -b mps/branch/2013-06-05/diag -s 182535
... //info.ravenbrook.com/project/mps/branch/2013-06-05/diag/code/arenavm.c - must resolve //info.ravenbrook.com/project/mps/master/code/arenavm.c#=182535 before submitting
# etc.
Resolve any merges resulting from the unshelve, using p4 resolve -as to quickly do the "safe" ones, and then doing the rest with p4 resolve as usual.
$ p4 resolve -as
//gdr-peewit/info.ravenbrook.com/project/mps/branch/2013-06-05/diag/code/arenavm.c - copy from //info.ravenbrook.com/project/mps/master/code/arenavm.c
# etc.
$ p4 resolve
No file(s) to resolve.
(The example output is from a real use case I ran just now.)
I never found a way to do that within perforce, but you can at least partially automate it.
Usually when I had to do something like that I'd check out the files in the branch I want to move things to, then use WinMerge to diff the branches and copy the changes over. Once that's done you can revert the changes in the original branch and check them in in the new branch.
It's not the best solution (no automatic checkout/add/delete of files on the new branch), but was the fastest method I came up with.
Not really.
You can of course simply open the files for edit in the new branch, and manually copy the changed files from the workspace of your main branch to the new branch's workspace. This is probably the easiest way if it just a few files.
Here are a few scripts that can be handy if a larger number of files are involved.
E.g., with the P4Shelf script you can create an archive of all your changed files, and later automatically open them in any branch with the changes restored.
Also, check out some other nifty scripts for Perforce by Jim Tilander.
To rephrase Gareth Rees' answer above in simple terms,
p4 unshelve -b target_branchspec -s changelist
:)
The easy answer is - no you can't. A quick perusal of the Perforce docs didn't come up with a ready cite for this, unfortunately, but in my experience any attempt to pull the rug out from under the Perforce server will result in your changes being lost which will leave you an unhappy camper.
Make a back up, create a new work area on the new branch, and re-apply your changes, perhaps using the diff/merge strategy outlined in Herms answer.

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