You can stop merge keeping all current changes in the working directory using stash. Witch stops the on going merge automatically.
In software development, Git (/ɡɪt/) is a distributed revision control and source code management (SCM) system with an emphasis on speed. Git was initially designed and developed by Linus Torvalds for Linux kernel development; it has since been adopted by many other projects. Every Git working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server. Git is free software distributed under the terms of the GNU General Public License version 2.