RE: Merging trunk changes into a branch

[John Daniel Doucette]

At 2001_08_22 Wednesday 09:48 AM -07004, Pyatt, Scott wrote:
> >From John Daniel Doucette:
> > According to CVS documentation, "Karl Fogel", red-bean.com, 'HEAD'
> > can be used anywheres a revision is required.   However, I have found that
>
> > it doesn't always work if used as a revision parameter to the 'cvs diff'
> > command.
>
> I've read a couple of times now that "HEAD" does not work consistantly with
> "cvs diff".  However, I have yet to hear anyone describe when it works, when
> it doesn't and what behavior it exhibits when it doesn't work.  Can you
> elaborate?
>
> Thanks,
> -Scott


Hi,

Say your repository has a trunk with tagged revisions trunk_1, trunk_2, 
trunk_3, ..., trunk_6.   Create a branch at trunk_2, called branch_trunk_2, 
and proceed to develop along the branch creating tagged branch revisions 
branch_1 branch_2, branch_3 ..., branch_5.    Now trunk_6 is the latest 
trunk version and should be equivelant to HEAD.   Branch_5 is the latest 
branch_trunk_2 version.  If you check out a working copy using '-r 
branch_trunk_2' or '-r branch_5' and do a 'cvs diff -r HEAD' you get NO 
changes at all.  If you do a 'cvs diff -r trunk_6' however, you get 
changes.  There doesn't appear to be a way to diff from a working branch to 
the HEAD of trunk without actually knowing the tag of the tip of 
trunk.   'cvs update -j HEAD' however does appear to notice changes, and 
will merge files from the tip of the trunk into your working branch 
directory.    However, if you check out a working copy of the latest trunk 
using either '-r trunk_6' or no -r at all,  you can do a cvs diff -r 
branch_trunk_2  and get changes.  This behaviour is exhibited on my machine 
with either WinCVS 1.2 command-line tools, and Cygwin CVS 1.11.
Come to think of it I have never actuall seen diff work using the '-r HEAD' 
option!


===================================
John Daniel Doucette, Sr. Software Designer

J. J. MacKay Canada Limited
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Phone           902.423.7727  x222
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