GNU Info

(cvs.info)Merging and keywords

---

Prev: Merging adds and removals Up: Branching and merging

---

Enter node , (file) or (file)node

Merging and keywords
====================

   If you merge files containing keywords (Note: Keyword
substitution), you will normally get numerous conflicts during the
merge, because the keywords are expanded differently in the revisions
which you are merging.

   Therefore, you will often want to specify the `-kk' (Note:
Substitution modes) switch to the merge command line.  By
substituting just the name of the keyword, not the expanded value of
that keyword, this option ensures that the revisions which you are
merging will be the same as each other, and avoid spurious conflicts.

   For example, suppose you have a file like this:

            +---------+
           _! 1.1.2.1 !   <-  br1
          / +---------+
         /
        /
     +-----+    +-----+
     ! 1.1 !----! 1.2 !
     +-----+    +-----+

   and your working directory is currently on the trunk (revision 1.2).
Then you might get the following results from a merge:

     $ cat file1
     key $Revision: 1.2 $
     . . .
     $ cvs update -j br1
     U file1
     RCS file: /cvsroot/first-dir/file1,v
     retrieving revision 1.1
     retrieving revision 1.1.2.1
     Merging differences between 1.1 and 1.1.2.1 into file1
     rcsmerge: warning: conflicts during merge
     $ cat file1
     <<<<<<< file1
     key $Revision: 1.2 $
     =======
     key $Revision: 1.1.2.1 $
     >>>>>>> 1.1.2.1
     . . .

   What happened was that the merge tried to merge the differences
between 1.1 and 1.1.2.1 into your working directory.  So, since the
keyword changed from `Revision: 1.1' to `Revision: 1.1.2.1', CVS tried
to merge that change into your working directory, which conflicted with
the fact that your working directory had contained `Revision: 1.2'.

   Here is what happens if you had used `-kk':

     $ cat file1
     key $Revision: 1.2 $
     . . .
     $ cvs update -kk -j br1
     U file1
     RCS file: /cvsroot/first-dir/file1,v
     retrieving revision 1.1
     retrieving revision 1.1.2.1
     Merging differences between 1.1 and 1.1.2.1 into file1
     $ cat file1
     key $Revision$
     . . .

   What is going on here is that revision 1.1 and 1.1.2.1 both expand
as plain `Revision', and therefore merging the changes between them
into the working directory need not change anything.  Therefore, there
is no conflict.

   There is, however, one major caveat with using `-kk' on merges.
Namely, it overrides whatever keyword expansion mode CVS would normally
have used.  In particular, this is a problem if the mode had been `-kb'
for a binary file.  Therefore, if your repository contains binary
files, you will need to deal with the conflicts rather than using `-kk'.