Calculator

GIT practice

Task:

• Clone the following repo: https://github.com/SergiiPiatakov/calculator.git .
• Using rebase -i swap the following commits: "fix truncation error" and "formatting: use tabs instead of spaces".
• Then sign them and create two patches using git format-patch.
• Then combine "improve calculation accuracy" and "fix truncation error" into one commit using rebase -i. Sign it.
• Then remove the top commit "formatting: use tabs instead of spaces" using git rebase -i - I really don't like tabs ;) .
• Rename the current remote on the "github". Add another remote: https://gitlab.com/SergiiPiatakov/calculator.git and call it "gitlab".
• Get code from the "gitlab" remote by git fetch, and explore it by git log gitlab/master.
• Then grab the commit: "add a multiplication operation" by git cherry-pick.
• Create your own patch about 5-15 lines (any changes).
• Push the result into your own repo.

Solution:

Clone the following repo:

$ git clone  https://github.com/SergiiPiatakov/calculator.git calculator
$ cd calculator

View all existing commits:

$ git log

From the list of commits we need to swap the last 2 commits - “fix truncation error” and “formatting: use tabs instead of spaces”:

$ git rebase -i HEAD^^

Then we get the following message:

• error: could not apply 4ad40a3... fix truncation error
• When you have resolved this problem, run "git rebase --continue".
• If you prefer to skip this patch, run "git rebase --skip" instead.
• To check out the original branch and stop rebasing, run "git rebase --abort".
• Could not apply 4ad40a3b4572deee4efc716e7bd6e6e4fda46dcf... fix truncation error

Now we need to resolve git conflict by hands. After conflict has been resolved:

$ git add calculator.cpp
$ git rebase --continue

Next command:

$ git show -n2
$ git rebase -i HEAD^^ 

Now put edit next to the commits names.

Then we need sign commits and perform next action twice, cause we have two commits:

$ git commit --amend -v -s
$ git rebase --continue

Run $ git log to check that last two commits are signed by you.

Create two patches using git format-patch:

$ git format-patch HEAD -2

Combine two commits into one:

$ git rebase -i HEAD^^^

Then use squash command.

Now sign our new commit and continue:

$ git commit -s --amend
$ git rebase --continue

Rename the current remote on the "github". Add another remote and call it "gitlab":

$ git remote
$ git remote rename origin github
$ git remote add gitlab https://gitlab.com/SergiiPiatakov/calculator.git
$ git remote show

Get code from the "gitlab" remote by git fetch, and explore it by git log gitlab/master:

$ git fetch gitlab
$ git log gitlab/master
$ git branch -av

Then grab the commit: "add a multiplication operation" by git cherry-pick:

$ git log --oneline gitlab/master
$ git cherry-pick e0ea21b

Now we have error "could not apply e0ea21b... add a multiplication operation" and we need to fix git conflict ($ git status and $ vim <file_with_conflict>). After that:

$ git cherry-pick --continue

Then we create our own patch (check code above) and push the result into repo.