Re: [PATCH 6/7] Add a "--clone" option to "stg branch"

From: Chuck Lever <cel@citi.umich.edu>
Date: Dec 1, 2005, 21:47 UTC
Message-ID: <438F6F89.7010004@citi.umich.edu>
In-Reply-To: <b0943d9e0512011305v3299f27au@mail.gmail.com>

Catalin Marinas wrote:

Show 18 quoted lines

> On 29/11/05, Chuck Lever <cel@netapp.com> wrote:
> 
>>Cloning a branch means creating a new branch and copying all of the
>>original branch's patches and its base to it.  Like creating a tag,
>>but this also preserves all the StGIT patches as well.
> 
> [...]
> 
>>--- a/stgit/commands/branch.py
>>+++ b/stgit/commands/branch.py
> 
> [...]
> 
>>+        print 'Cloning current branch to "%s"...' % clone
> 
> 
> I would put a comma after this line and add sys.stdout.flush(). So
> that 'done' is shown on the same line.

d'oh! that's left over from when the Series.clone() method actually printed the name of each patch as it was cloning. fixed.

Show 16 quoted lines

> [...]
> 
>>--- a/stgit/stack.py
>>+++ b/stgit/stack.py
> 
> [...]
> 
>>+    def clone(self, target_series):
>>+        """Clones a series
>>+        """
> 
> 
> Wouldn't it be easier to do a recursive copy at the directory level
> (.git/patches/<branch> into .git/patches/<clone> and
> .git/refs/bases/<branch> into .git/refs/bases/<clone>)? Is there
> anything that could go wrong if we do this?

well, then you'd also clone any junk files that were left in there (for example, development notes).

also, by doing this a patch at a time, it gives the ability to hook in additional functionality in the future, in case we want to do something special to each newly cloned patch, like mechanically change the patch names, or automatically add some annotation, for example.

it also automatically converts an old-style branch (patches and series control files in same directory) to a new-style branch (patches in separate directory from series control files).

it follows the same basic pattern of logic as "stg pick". cloning a branch is kind of like 'picking' all of it's patches into a new branch.

but finally (and most practically speaking), i hunted around for Python code to copy a directory hierarchy, and interestingly enough it looks about as complicated (or maybe more complicated) than the clone implementation i finally came up with, which is only about 30 lines. i suppose we could just do a "os.system('cp -r yada yada')" but that's just lame ;^) and it only works on UNIX.

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