RE: Main branch tips

[Jim.Hyslop]

Andy Jones [mailto:address@hidden wrote:
> > > Is there some way (or special tag) which will allow me to 
> refer to the
> > > "tips" of main branch, so I can use:
> >
> >yes, there is a special tag, HEAD
Be aware that with the diff command, HEAD means "the head revision of the
currently-checked-out branch" (in this context, "branch" also includes the
trunk). For all other commands, HEAD means the head revision of the trunk.

> >(and another one is BASE, which refers to the revision you last checked
> >out in your current working directory)

> So, if I do a cvs checkout without a -r then I get the HEAD revision?
Maybe. If the source is already checked out using a tag, then it uses the
tag, e.g.:

cvs co -ratag amodule
cvs co amodule

The second checkout will still use the tag 'atag'.

> And in that case there will be no difference between 'cvs 
> update -j <rev1>' 
> and 'cvs update -j <rev1> -j HEAD' ?
> 
> Is that correct?

No. 

With merging, it is the _first_ -j flag that is optional, and that does not
default to HEAD but to BASE (or, more accurately, to the "ancestor revision"
- the manual
http://www.cvshome.org/docs/manual/cvs-1.11.7/cvs_16.html#SEC153 defines
"ancestor revision" more succinctly than I can).

The first command merges the difference between the ancestor revision and
<rev1> into your source. The second command will merge the difference
between <rev1> and HEAD into your source.

-- 
Jim Hyslop
Senior Software Designer
Leitch Technology International Inc. (http://www.leitch.com)
Columnist, C/C++ Users Journal (http://www.cuj.com/experts)