Answer by Matheus Felipe for Undoing a git rebase

Following the solution of @Allan and @Zearin, I wish I could simply do a comment though but I don't enough reputation, so I have used the following command:

Instead of doing git rebase -i --abort (note the -i) I had to simply do git rebase --abort (without the -i).

Using both -i and --abort at the same time causes Git to show me a list of usage/options.

So my previous and current branch status with this solution is:

matbhz@myPc /my/project/environment (branch-123|REBASE-i)
$ git rebase --abort

matbhz@myPc /my/project/environment (branch-123)
$