Re: [Sablevm-developer] suggestion: sablevm developer doc

[Chris P. <chr...@ma...>]

Prof. Etienne M. Gagnon wrote:

>OK guys, you want a proof that CVS is broken.
>
>I'll eventually prepare an example for you, but not now; I don't have
>the time.  The example goes along the lines of: You make 2 branches,
>you "cvs add ; cvs commit" distinct files with the same name on the
>respective branches, then CVS loses one of the two files without
>warning.
>
>Also, I encourage you to experiment maintaining a branch and trying to
>merge trunk updates into the branch.  CVS is good at the reverse
>(e.g. merging branch modifs into the trunk), but it not very helpful
>at tracking trunk changes in a branch.
>  
>
No ... the way Mozilla works is every once in a while, it takes a 
snapshot of development on the trunk and creates a branch.  There is a 
new branch for every release.  There is no maintenance of the branch ... 
you simply take your trunk snapshot and keep working on the branch until 
it is fixed.  Then, when the release occurs, you merge the branch 
changes into the trunk (which CVS is good at, as you said).  The whole 
point is that once the branch is made, trunk changes don't affect the 
branch anymore -- and they shouldn't either ... it will have to wait 
until the next release.

http://www.mozilla.org/roadmap.html

>FYI, you might want to learn about how robust merging works.  PRCS
>identified 14 distinct situations:
>
>http://prcs.sourceforge.net/merge.html
>
>The interesting thing is that PRCS actually asks you before performing
>an action.
>
>Additional reading identifying some of CVS's problems & advantages:
>http://prcs.sourceforge.net/cvs-vs-prcs.html
>http://prcs.sourceforge.net/kingdon.html
>  
>
I've read all the PRCS stuff before, but it has problems of its own too 
(ask Ondrej).  I don't know what SubVersion is like, I would be open to 
trying it.  But I don't know if SF supports it.

Chris

>On Tue, Mar 18, 2003 at 07:23:38AM -0500, Chris Pickett wrote:
>  
>
>>Grzegorz B. Prokopski wrote:
>>
>>    
>>
>>>W li?cie z wto, 18-03-2003, godz. 01:17, Prof. Etienne M. Gagnon pisze: 
>>>
>>>
>>>      
>>>
>>>>On Mon, Mar 17, 2003 at 03:53:20PM -0500, Chris Pickett wrote:
>>>>  
>>>>
>>>>        
>>>>
>>>>>How about . . . we just have a development branch and the main trunk. 
>>>>>Anyone can hack away on the development branch (obviously trying not to 
>>>>>break things), and then once in a while Etienne merges changes into the 
>>>>>main trunk.  Or some other such multi-developer version control idiom.
>>>>>    
>>>>>
>>>>>          
>>>>>
>>>>The problem, with CVS, is that when you add something new on a branch,
>>>>it is considered as head and thus shows up in the main trunk and in
>>>>the Changelog.
>>>>  
>>>>
>>>>        
>>>>
>>>Are you sure? CVS docs say sth. rather opposite, see
>>>http://www.loria.fr/~molli/cvs/doc/cvs_5.html#SEC49
>>>
>>>"CVS allows you to isolate changes onto a separate line of development,
>>>known as a branch. When you change files on a branch, those changes do
>>>not appear on the main trunk or other branches."
>>>
>>>Projects like Mozilla use CVS in the model of HEAD (unstable,
>>>development version) and branches (stable releases). If CVS weren't
>>>suitable for this - would they use it?
>>>
>>>
>>>      
>>>
>>I kind of like the Mozilla model of development.  I think it makes more 
>>sense than having a development branch, actually.  It says, "If you want 
>>a stable release, don't check out from CVS but rather get a tarball.  
>>And if you really want to check out the sources in the tarball from the 
>>release branch, you can."
>>
>>CVS may have problems but then again 99% of projects use it so it can't 
>>be that severely broken.
>>
>>Chris
>>    
>>
>
>  
>