Git cherry pick those commits that contain a keyword (tracking id)

Question

For code review purpose, I want to

1. cherry pick specific commits
2. create a new branch with them and
3. push that branch to remote

so that I can give branch url to peers for review.

I want to create a shell script and issue simple command like

git-review <trackingID>

It gives output as below

Branch <currentgitusername>_<trackingID> created and pushed to remote.

I put together a script that does above mentioned steps.

#!/bin/bash

if [ -z $1 ]; then
    echo "Rationale: Cherry pick all commits in master, matching the tracking ID and create a new branch.";
    echo "";
    echo "Usage:  $0 traackingID";
    echo "";
    exit 1;
fi

#If $1 doesn't match a AGW-<number> pattern, thrown an error
#Best of luck if you did not add add tracking ID in commits.

user="$(id -u -n)" > /dev/null

echo "You are - $user"

branchname=$user"_"$1"_review"

echo "Creating branch - $branchname"

git checkout -b $branchname > /dev/null

git log master --pretty=%H --grep="$1" | while read rev
do
  echo $rev
 # git cherry-pick $rev > /dev/null
done

#git push &> /dev/null

echo "Created branch, cherry picked, pushed to remote. Now switching back to master. Bye."

git checkout master

But got stuck in couple of places.

1. I want to validate the trackingID format. It should be AGW-<somenumber>

2. Looks like the cherry-picks have merge issues.

   myname@mymachine ~/myproj
   $ ../git-review.sh AGW-1234
   You are - myname
   Creating branch - myname_AGW-1234_review
   Switched to a new branch 'myname_AGW-1234_review'
   2dfafa89e10062e7cfccb1d7a947ebb848c40cc6
   The previous cherry-pick is now empty, possibly due to conflict resolution.
   If you wish to commit it anyway, use:
   
       git commit --allow-empty
   
   Otherwise, please use 'git reset'
   1e295000bc3d80880518c9cac5e34ef3b28fc29e
   error: Your local changes to the following files would be overwritten by merge:
           rest-service/src/main/java/package/HealthCheckDAOImpl.java
   Please, commit your changes or stash them before you can merge.
   

Am I cherry picking in wrong way ? Also, please suggest any changes to make this script robust.

Answer 1

As already pointed in the comments by @novelocrat, You are cherry picking in the wrong order. By default, git log will output from the latest commit to the first commit. To do this, either feed in the output of git log --oneline to tac, or use the --reverse flag:

git log --oneline | tac
git log --oneline --reverse

The second option is obviously prefered, because that ensures line by line output, while the first (using tac) will need to be fed all the input in one go.

---

Also, since you are creating a new branch out of master, when you do git checkout -b $branchname.

When you do that, all the history of the current branch is picked from that.

So you need to create an orphaned git branch, like mentioned here.