How to reverse apply a stash?

Question

I have a small patch saved away in my git stash. I've applied it to my working copy using git stash apply. Now, I'd like to back out those changes by reverse applying the patch (kind of like what git revert would do but against the stash).

Does anyone know how to do this?

Clarification: There are other changes in my working copy. My particular case is hard to describe but you can imagine some debugging or experimental code that's in the stash. Now it's mixed in my working copy with some other changes and I'd like to see the effect with and without the changes from the stash.

It doesn't look like stash supports this currently, but a git stash apply --reverse would be a nice feature.

Answer 1

According to the git-stash manpage, "A stash is represented as a commit whose tree records the state of the working directory, and its first parent is the commit at HEAD when the stash was created," and git stash show -p gives us "the changes recorded in the stash as a diff between the stashed state and its original parent.

To keep your other changes intact, use git stash show -p | patch --reverse as in the following:

$ git init
Initialized empty Git repository in /tmp/repo/.git/

$ echo Hello, world >messages

$ git add messages

$ git commit -am 'Initial commit'
[master (root-commit)]: created 1ff2478: "Initial commit"
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 messages

$ echo Hello again >>messages

$ git stash

$ git status
# On branch master
nothing to commit (working directory clean)

$ git stash apply
# On branch master
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#       modified:   messages
#
no changes added to commit (use "git add" and/or "git commit -a")

$ echo Howdy all >>messages

$ git diff
diff --git a/messages b/messages
index a5c1966..eade523 100644
--- a/messages
+++ b/messages
@@ -1 +1,3 @@
 Hello, world
+Hello again
+Howdy all

$ git stash show -p | patch --reverse
patching file messages
Hunk #1 succeeded at 1 with fuzz 1.

$ git diff
diff --git a/messages b/messages
index a5c1966..364fc91 100644
--- a/messages
+++ b/messages
@@ -1 +1,2 @@
 Hello, world
+Howdy all

Edit:

A light improvement to this is to use git apply in place of patch:

git stash show -p | git apply --reverse

Alternatively, you can also use git apply -R as a shorthand to git apply --reverse.

I've been finding this really handy lately...

Answer 2

git checkout -f

will remove any non-commit changes.

Answer 3

git stash[save] takes your working directory state, and your index state, and stashes them away, setting index and working area to HEAD version.

git stash apply brings back those changes, so git reset --hard would remove them again.

git stash pop brings back those changes and removes top stashed change, so git stash [save] would return to previous (pre-pop) state in this case.

Answer 4

The V1 git man page had a reference about un-applying a stash. The excerpt is below.

The newer V2 git man page doesn't include any reference to un-applying a stash but the below still works well

Un-applying a Stash In some use case scenarios you might want to apply stashed changes, do some work, but then un-apply those changes that originally came from the stash. Git does not provide such a stash un-apply command, but it is possible to achieve the effect by simply retrieving the patch associated with a stash and applying it in reverse:

$ git stash show -p stash@{0} | git apply -R

Again, if you don’t specify a stash, Git assumes the most recent stash:

$ git stash show -p | git apply -R

You may want to create an alias and effectively add a stash-unapply command to your Git. For example:

$ git config --global alias.stash-unapply '!git stash show -p | git apply -R'
$ git stash apply
$ #... work work work
$ git stash-unapply

Answer 5

This is long over due, but if i interpret the problem correctly i have found a simple solution, note, this is an explanation in my own terminology:

git stash [save] will save away current changes and set your current branch to the "clean state"

git stash list gives something like: stash@{0}: On develop: saved testing-stuff

git apply stash@{0} will set current branch as before stash [save]

git checkout . Will set current branch as after stash [save]

The code that is saved in the stash is not lost, it can be found by git apply stash@{0} again.

Anywhay, this worked for me!

Answer 6

How to reverse apply a stash?

Apart from what others have mentioned, easiest way is first do

git reset HEAD

and then checkout all local changes

git checkout . 

Answer 7

you can apply two commands

git reset . // to reverse the files

then

git checkout . // to reverse the changes

Answer 8

You can follow the image i shared to unstash if u accidentally tapped stashing.

Answer 9

In addition to @Greg Bacon answer, in case binary files were added to the index and were part of the stash using

git stash show -p | git apply --reverse

may result in

error: cannot apply binary patch to '<YOUR_NEW_FILE>' without full index line
error: <YOUR_NEW_FILE>: patch does not apply

Adding --binary resolves the issue, but unfortunately haven't figured out why yet.

 git stash show -p --binary | git apply --reverse

Answer 10

git stash show -p | git apply --reverse

Warning, that would not in every case: "git apply -R"^(man) did not handle patches that touch the same path twice correctly, which has been corrected with Git 2.30 (Q1 2021).

This is most relevant in a patch that changes a path from a regular file to a symbolic link (and vice versa).

See commit b0f266d (20 Oct 2020) by Jonathan Tan (jhowtan).
^{(Merged by Junio C Hamano -- gitster -- in commit c23cd78, 02 Nov 2020)}

apply: when -R, also reverse list of sections

^{Helped-by: Junio C Hamano
Signed-off-by: Jonathan Tan}

A patch changing a symlink into a file is written with 2 sections (in the code, represented as "struct patch"): firstly, the deletion of the symlink, and secondly, the creation of the file.

When applying that patch with -R, the sections are reversed, so we get: (1) creation of a symlink, then (2) deletion of a file.

This causes an issue when the "deletion of a file" section is checked, because Git observes that the so-called file is not a file but a symlink, resulting in a "wrong type" error message.

What we want is: (1) deletion of a file, then (2) creation of a symlink.

In the code, this is reflected in the behavior of previous_patch() when invoked from check_preimage() when the deletion is checked.
Creation then deletion means that when the deletion is checked, previous_patch() returns the creation section, triggering a mode conflict resulting in the "wrong type" error message.

But deletion then creation means that when the deletion is checked, previous_patch() returns NULL, so the deletion mode is checked against lstat, which is what we want.

There are also other ways a patch can contain 2 sections referencing the same file, for example, in 7a07841c0b ("git-apply: handle a patch that touches the same path more than once better", 2008-06-27, Git v1.6.0-rc0 -- merge). "git apply -R"^(man) fails in the same way, and this commit makes this case succeed.

Therefore, when building the list of sections, build them in reverse order (by adding to the front of the list instead of the back) when -R is passed.

Answer 11

This is in addition to the above answers but adds search for the git stash based on the message as the stash number can change when new stashes are saved. I have written a couple of bash functions:

apply(){
  if [ "$1" ]; then
    git stash apply `git stash list | grep -oPm1 "(.*)(?=:.*:.*$1.*)"`
  fi
}
remove(){
  if [ "$1" ]; then
    git stash show -p `git stash list | grep -oPm1 "(.*)(?=:.*:.*$1.*)"` | git apply -R
    git status
  fi
}

1. Create stash with name (message) $ git stash save "my stash"
2. To appply named $ apply "my stash"
3. To remove named stash $ remove "my stash"

Answer 12

I had a similar issue myself, I think all you need to do is git reset --hard and you will not lose your changes or any untracked changes.

If you read the docs in git stash --help it states that apply is "Like pop, but do not remove the state from the stash list" so the state still resides there, you can get it back.

Alternatively, if you have no conflicts, you can just git stash again after testing your changes.

If you do have conflicts, don't worry, git reset --hard won't lose them, as "Applying the state can fail with conflicts; in this case, it is not removed from the stash list. You need to resolve the conflicts by hand and call git stash drop manually afterwards."

Answer 13

For me, i had just typed the wrong name of the repository when checking out. So there literally was not remote to pull.

So, in addition to checking the casing, check the branch name spelling, or better yet, copy and paste it -to rule it out.