lab 34 Rebasing

Goals

Use the rebase command rather than the merge command.

Ok, we are back in time before the first merge and we want to get the changes in master into our greet branch.

This time we will use the rebase command instead of the merge command to bring in the changes from the master branch.

Execute:

git checkout greet
git rebase master
git hist

Output:

$ go greet
Switched to branch 'greet'
$
$ git rebase master
First, rewinding head to replay your work on top of it...
Applying: added Greeter class
Applying: hello uses Greeter
Applying: updated Rakefile
$
$ git hist
* d15df76 2013-10-06 | Updated Rakefile (HEAD, greet) [Ismail Dhorat]
* 2fda7cb 2013-10-06 | Hello uses Greeter [Ismail Dhorat]
* 343d947 2013-10-06 | Added greeter class [Ismail Dhorat]
* 313c04d 2013-10-06 | Added README (master) [Ismail Dhorat]
* b3e19a3 2013-10-06 | Added a Rakefile. [Ismail Dhorat]
* 14f09c0 2013-10-06 | Moved hello.rb to lib [Ismail Dhorat]
* 1fed2ec 2013-10-06 | Add an author/email comment [Ismail Dhorat]
* dc44f2e 2013-10-06 | Added a comment (v1) [Ismail Dhorat]
* 5ec54fd 2013-10-06 | Added a default value (v1-beta) [Ismail Dhorat]
* e606a20 2013-10-06 | Using ARGV [Ismail Dhorat]
* 5d95e74 2013-10-06 | First Commit [Ismail Dhorat]

Merge VS Rebase 01

The final result of the rebase is very similar to the merge. The greet branch now contains all of its changes, as well as all the changes from the master branch. However, the commit tree is quite different. The commit tree for the greet branch has been rewritten so that the master branch is a part of the commit history. This leaves the chain of commits linear and much easier to read.

When to Rebase, When to Merge? 02

Don’t use rebase …

If the branch is public and shared with others. Rewriting publicly shared branches will tend to screw up other members of the team.
When the exact history of the commit branch is important (since rebase rewrites the commit history).

Given the above guidelines, I tend to use rebase for short-lived, local branches and merge for branches in the public repository.