How can I remove an applied git patch?

Question

I have a git repo, where we apply many patches in test environment.

git apply --stat --check --ignore-whitespace /home/kent/Desktop/patches/test.patch --exclude .gitignore  git am -s --ignore-whitespace /home/kent/Desktop/patches/test.patch --exclude .gitignore --exclude .gitignore 

If I have to remove the patch and apply a new one, at present I clone the live content and reapply all the test patches and push again. This process is somehow cumbersome and also leads to errors at times I also miss one or two patches.

I wanted to know if there is a way to remove a patch and apply the new one

Also, to add one way is there if we commit each time to the patch and then i can use:

git revert <<commit id>> 

The above does not work for me at all times.

Answer 1

TL;DR

You can revert a patch with:

$ git apply -R <patch> 

---

You can generate a patch either by one of the following:

This will generate a patch from a diff

$ git diff --patch > 0001-some-modifications.patch 

If you want to generate a patch for just the HEAD commit:

$ git show --patch HEAD^ > 0001-some-modifications.patch 

You can generate a patch for the previous 3 commits from HEAD:

$ git show --patch HEAD~3 > 0001-some-modifications.patch 

You can apply the patch by:

$ git apply -- 0001-some-modifications.patch 

You can revert a patch with:

$ git apply -R <patch> 

When you generate a patch it is just a diff with metadata; files, line numbers adds/removes; something along the following:

commit 9dad147cbf16befecdef2e812c1249499bdef5ac Author: My Name <[email protected]> Date:   Mon Dec 21 20:46:01 2015 +0000      Example commit message.  diff --git a/src/example.md b/src/example.md new file mode 100644 index 0000000..ab73512 --- /dev/null +++ b/src/example.md @@ -0,0 +1,3 @@ +# Example document + + Hello World 

So when you use git apply you're essentially applying the edits as per to the tree.

When you then run git apply -R git will simply do the opposite to the patch.