A.10.2 commit examples

A.10.2.1 Committing to a branch

You can commit to a branch revision (one that has an even number of dots) with the ‘-r’ option. To create a branch revision, use the ‘-b’ option of the rtag or tag commands (see Branching and merging). Then, either checkout or update can be used to base your sources on the newly created branch. From that point on, all commit changes made within these working sources will be automatically added to a branch revision, thereby not disturbing main-line development in any way. For example, if you had to create a patch to the 1.2 version of the product, even though the 2.0 version is already under development, you might do:

$ cvs rtag -b -r FCS1_2 FCS1_2_Patch product_module
$ cvs checkout -r FCS1_2_Patch product_module
$ cd product_module
[[ hack away ]]
$ cvs commit

This works automatically since the ‘-r’ option is sticky.

A.10.2.2 Creating the branch after editing

Say you have been working on some extremely experimental software, based on whatever revision you happened to checkout last week. If others in your group would like to work on this software with you, but without disturbing main-line development, you could commit your change to a new branch. Others can then checkout your experimental stuff and utilize the full benefit of CVS conflict resolution. The scenario might look like:

[[ hacked sources are present ]]
$ cvs tag -b EXPR1
$ cvs update -r EXPR1
$ cvs commit

The update command will make the ‘-r EXPR1’ option sticky on all files. Note that your changes to the files will never be removed by the update command. The commit will automatically commit to the correct branch, because the ‘-r’ is sticky. You could also do like this:

[[ hacked sources are present ]]
$ cvs tag -b EXPR1
$ cvs commit -r EXPR1

but then, only those files that were changed by you will have the ‘-r EXPR1’ sticky flag. If you hack away, and commit without specifying the ‘-r EXPR1’ flag, some files may accidentally end up on the main trunk.

To work with you on the experimental change, others would simply do

$ cvs checkout -r EXPR1 whatever_module