I ran into a merge conflict. How do I abort the merge?

Since your pull was unsuccessful then HEAD (not HEAD^) is the last "valid" commit on your branch:

git reset --hard HEAD

The other piece you want is to let their changes over-ride your changes.

Older versions of git allowed you to use the "theirs" merge strategy:

git pull --strategy=theirs remote_branch

But this has since been removed, as explained in this message by Junio Hamano (the Git maintainer). As noted in the link, instead you would do this:

git fetch origin
git reset --hard origin

I think it's git reset you need.

Beware that git revert means something very different to, say, svn revert - in Subversion the revert will discard your (uncommitted) changes, returning the file to the current version from the repository, whereas git revert "undoes" a commit.

git reset should do the equivalent of svn revert, that is, discard your unwanted changes.

For git >= 1.6.1:

git merge --abort

For older versions of git, this will do the job:

git reset --merge

or

git reset --hard

In this particular use case, you don't really want to abort the merge, just resolve the conflict in a particular way.

There is no particular need to reset and perform a merge with a different strategy, either. The conflicts have been correctly highlighted by git and the requirement to accept the other sides changes is only for this one file.

For an unmerged file in a conflict git makes available the common base, local and remote versions of the file in the index. (This is where they are read from for use in a 3-way diff tool by git mergetool.) You can use git show to view them.

# common base:
git show :1:_widget.html.erb

# 'ours'
git show :2:_widget.html.erb

# 'theirs'
git show :3:_widget.html.erb

The simplest way to resolve the conflict to use the remote version verbatim is:

git show :3:_widget.html.erb >_widget.html.erb
git add _widget.html.erb

Or, with git >= 1.6.1:

git checkout --theirs _widget.html.erb

You can either abort the merge step:

git merge --abort

else you can keep your changes (on which branch you are)

git checkout --ours file1 file2 ...

otherwise you can keep other branch changes

git checkout --theirs file1 file2 ...

Might not be what the OP wanted, but for me I tried to merge a stable branch to a feature branch and there were too many conflicts. I didn't manage to reset the changes since the HEAD was changed by many commits, So the easy solution was to force checkout to a stable branch. you can then checkout to the other branch and it will be as it was before the merge.

git checkout -f master

git checkout side-branch

To avoid getting into this sort of trouble one can expand on the git merge --abort approach and create a separate test branch before merging.

Case: You have a topic branch, it wasn't merged because you got distracted/something came up/you know but it is (or was) ready.

Now is it possible to merge this into master?

Work in a test branch to estimate / find a solution, then abandon the test branch and apply the solution in the topic branch.

# Checkout the topic branch
git checkout topic-branch-1

# Create a _test_ branch on top of this
git checkout -b test

# Attempt to merge master
git merge master

# If it fails you can abandon the merge
git merge --abort
git checkout -
git branch -D test  # we don't care about this branch really...

Work on resolving the conflict.

# Checkout the topic branch
git checkout topic-branch-1

# Create a _test_ branch on top of this
git checkout -b test

# Attempt to merge master
git merge master

# resolve conflicts, run it through tests, etc
# then
git commit <conflict-resolving>

# You *could* now even create a separate test branch on top of master
# and see if you are able to merge
git checkout master
git checkout -b master-test
git merge test

Finally checkout the topic branch again, apply the fix from the test branch and continue with the PR. Lastly delete the test and master-test.

Involved? Yes, but it won't mess with my topic or master branch until I'm good and ready.

I found the following worked for me (revert a single file to pre-merge state):

git reset *currentBranchIntoWhichYouMerged* -- *fileToBeReset*