How to quickly find out the changelist deleting a line - perforce

I need to find out which changelist deleted a particular line from a file. This file is regularly updated by many people. I have 2 changelist at hand, one has the line and the other does not. The problem is, there are numerous changes in between.
Any pointer is appreciated!
[UPDATE]
I found this script, http://projects.joelinoff.com/p4tools/p4-whodunit.py, but it does not work for me:
$~/tmp/p4-whodunit.py --help
: No such file or directory
$~/tmp/p4-whodunit.py //depot/mybranch/file1
: No such file or directory
Not familiar with python, not sure what to do with it.

Use "p4 annotate -a" to find out when the line was last present; the following revision is the one that removed it.
In this example, line A was added in revision 2, and removed (replaced by B) in revision 3:
C:\test\local\dvcs\i\deltas>p4 annotate -a foo
//stream/main/i/deltas/foo#3 - edit change 50625 (text)
1-1: 1:
2-2: 1: A
3-3: 1: B
So to answer the question of "in what changelist did line A get deleted?" I can do:
C:\test\local\dvcs\i\deltas>p4 annotate -a foo | grep A
2-2: 1: A
C:\test\local\dvcs\i\deltas>p4 files foo#3
//stream/main/i/deltas/foo#3 - edit change 50625 (text)

Use P4V's Timelapse View. It will show the changelist that added the line, and the changelist that deleted the line.

Related

How should be paths to p4 sync -L formatted

I'm trying to figure out what is correct syntax for p4 sync -L. When I try p4 sync -L //one/of/my/files it complains that revision is not specified while if I try p4 sync -L //one/of/my/files#1234 it complains that # and # are illegal.
Well, the documentation says:
a list of valid file arguments in full depot syntax with a valid revision number
Revision numbers are #1, #17, etc. The # syntax is used to reference a label name, client name, or changelist number, which are not revision numbers.
For more details on this, check [p4 help revisions][2]; as it says, you want:
`file#n Revision specifier: The nth revision of file.`
So, specify //one/of/my/files#17, assuming that revision 17 is the revision of that file that you want to sync.
To see the revisions of your files, use p4 filelog //one/of/my/files.

The diff command for files with empty content

If I want to get the difference between the 2 directories, I use the command below:
diff -aruN dir1/ dir2/ > dir.patch
so the dir.patch file should comprise all differences I want, right?
But if dir2/ contains a file with empty content, and that file is not existent in dir1/, for example,
dir1/
dir2/empty_content_file.txt ------ with empty content.
Then the diff command will not generate any patch for empty_content_file.txt, but it is a needed file.
Is there any expertise or alternative way to do this?
Thank you in advance.
It's because you're using -N option, which is added to explicitly treat absent file as empty. man diff says :
-N, --new-file
treat absent file as empty
The screenshot below shows the operation of "diff -aru" command for inexistent files in the first directory, a message "Only in xxx" will show.

Getting the change number of the first revision of a file in Perforce?

Is there a way to retrieve the change of the first revision of a file in Perforce? Sometimes I want to read the job description of the change that introduced a file, in order to learn what the file does, as well as to find related CRs for more information. I'm looking for something in the command line, e.g.
p4 <something> <file>
Ah, never mind, I found the subcommand I needed, p4 fstat, just after posting the question.
$ p4 fstat cama_Preempt#1
... depotFile //depot/MMA/products/CAMA/main/src/testScripts/cama_Preempt
... clientFile /ext1/acheong/CAMA/main/src/testScripts/cama_Preempt
... isMapped
... headAction add
... headType text
... headTime 1174070670
... headRev 1
... headChange 168703
... headModTime 1174070479
... haveRev 1
The headChange field shows the change number.

Perforce: How to find the original number of a change list

In perforce changelists get renumbered on submission. So for e.g. when the changelist was created it would be numbered 777 , but on submission of changelist it would get renumbered to say 790.
My question is how do I get the new CL number (790) , if I know the old CL number 777 , or vice versa ?
If you really want the original changelist number, that can be retrieved from Perforce without having to embed the original changelist number in the description. You can use the -ztag command line option to get at it. And you can only get at it through the 'changes' command (as far as I know):
d:\sandbox>p4 submit -c 24510
Submitting change 24510.
Locking 1 files ...
edit //depot/testfile.txt#2
Change 24510 renamed change 24512 and submitted.
d:\sandbox>p4 -ztag changes -m1 //depot/testfile.txt
... change 24512
... time 1294249178
... user test.user
... client client-test.user
... status submitted
... oldChange 24510
... desc <enter description here>
<saved
As pointed out, it's probably not that useful. However, I did want to note that it's possible to get at it.
The only way I can think of is adding the original changelist number as part of the changelist description field. First, you'll need a script to store the original changelist number:
#!/bin/env perl
$id = $ARGV[0];
open (CHANGE_IN, "p4 change -o $id|");
open (CHANGE_OUT, "|p4 change -i $id");
while (<CHANGE_IN>)
{
if (/^Description:/ and not /ORIGID/)
{
s/(^Description:)(.*)$/$1 ORIGID $id. $2/;
}
print CHANGE_OUT $_;
}
close (CHANGE_IN);
close (CHANGE_OUT);
Save this as origid.pl on the Perforce server with the executable bit set. Then setup a trigger with p4 triggers.
Triggers:
add_origid change-submit //depot/... /usr/bin/origid.pl %change%
Version 2012.1 of Perforce introduced the -O (capital oh) argument to p4 describe, which allows you to query a changelist by its original number (before being renumbered by p4 submit).
I find this very helpful, since I often find myself keeping notes about a changeset before it is submitted, then forgetting to note what it was renumbered to on submission.
So if I have a note talking about change 12300, I can now see what it refers to by typing:
p4 describe -s -O 12300
and having Perforce tell me:
Change 12345 by me#myhost on 2013/10/31 00:00:00
Fix that thing I wrote that note about
Affected files ...
... //Proj/MAIN/foo.c
The ztag method mentioned earlier can be used to find the old changelist number of a submitted change:
> p4 -ztag describe -s 12345 | grep oldChange
... oldChange 12300
Adding to Eric Miller's reply, because I can't comment (not enough points):
to just emit the 1 number
p4 -ztag describe $ORIG | sed -e 's/^\.\.\. oldChange //;t-ok;d;:-ok'
e.g.
OLD=$(p4 -ztag describe $ORIG | sed -e 's/^\.\.\. oldChange //;t-ok;d;:-ok')
or if you want to look up many numbers, this will output a map of new old on each line (may be useful with the "join" command). If there is no old commit, then it re-emits the new commit.
p4 -ztag describe 782546 782547 ... | sed -e '${x;p};s/^\.\.\. change //;t-keep;b-next;:-keep;x;/./p;g;G;s/\n/ /;x;d;:-next;s/^\.\.\. oldChange //;t-ok;d;:-ok;H;x;s/ .*\n/ /;x;d;'
I tried to avoid using GNU extensions to sed.
Unless you do something like Tim suggests the old change list number will be lost on submission.
Change list numbers are only temporary until you actually submit. So if you create a new change list (777 say) and then decide to delete it, the next change list you create will be 778.
It can be a bit more elegant if you use the P4 Python module.
i.e.
import P4
p4 = P4.P4()
p4.connect() # having a valid p4 workspace/connection is on you :)
c = p4.run_describe('969696') # describe a Submitted, renumbered changelist, i.e. 969696
old_pending_cl_number = c['oldChange'] # print out prior/pending CL# if this exists.
Cheers

Resolving patch conflicts manually [duplicate]

I'm having trouble applying a patch to my source tree, and it's not the usual -p stripping problem. patch is able to find the file to patch.
Specifically, my question is how to read / interpret the .rej files patch creates when it fails on a few hunks. Most discussions of patch/diff I have seen don't include this.
A simple example:
$ echo -e "line 1\nline 2\nline 3" > a
$ sed -e 's/2/b/' <a >b
$ sed -e 's/2/c/' <a >c
$ diff a b > ab.diff
$ patch c < ab.diff
$ cat c.rej
***************
*** 2
- line 2
--- 2 -----
+ line b
As you can see: The old file contains line 2 and the new file should contain line b. However, it actually contains line c (that's not visible in the reject file).
In fact, the easiest way to resolve such problems is to take the diff fragment from the .diff/.patch file, insert it at the appropriate place in the file to be patched and then compare the code by hand to figure out, what lines actually cause the conflict.
Or - alternatively: Get the original file (unmodified), patch it and run a three way merge on the file.
Wiggle is a great tool for applying .rej files when patch does not succeed.
I'm not an expert on dealing with patch files, but I'd like to add some clarity on how to read them based on my understanding of the information they contain.
Your .rej files will tell you:
the difference between the original and the .rej file;
where the problem code starts in the original file, how many lines it goes on
for in that file;
and where the code starts in the new file, and how many lines it goes on for in that file.
So given this message, noted in the beginning of my .rej file:
diff a/www/js/app.js b/www/js/app.js (rejected hunks)
## -4,12 +4,24 ##
I see that for my problem file (www/js/app), the difference between the original (noted as a/www/js/app.js on the first line) and the .rej file (noted as b/www/js/) starts on line 4 of the original and goes on for 12 lines (the part before the comma in ## -4,12, +4,24 ## on line two), and starts on line 4 of the new version of the file and goes on for 24 lines (the part after the comma in ## -4,12, +4,24 ##.
For further information, see the excellent overview of patch files (containing the information I note above, as well as details on lines added and/or between file versions) at http://blog.humphd.org/vocamus-906/.
Any corrections or clarifications welcome of course.

Resources