Gitting More Out of Git

Jordan Kasper | @jakerella

Danger!

Git is Distributed

A centralized VCS

https://docs.joomla.org/Dvcs

A distributued VCS

https://docs.joomla.org/Dvcs

A distributued VCS (in practice)

https://docs.joomla.org/Dvcs

Remotes

A "remote" is just a repo outside your local environment.

Cloning


~$ git clone git@github.com:jakerella/foo.git repo
        
~$ cd repo
        
~/repo$ git branch -a
* main
  remotes/origin/main

Cloning creates a remote called "origin",
which appears as a local branch.

Tracking

Any local branch can "track" a remote URL:


~/repo$ git branch -vv
* main               b956c45c [origin/main] Initial commit
  some-local-branch  a74b2950 Implemented that cool feature

Note the double "vv" here. A single "v" will not show you the remote branch being tracked.

Wherezitat?


~/repo$ git remote -v
origin  git@github.com:jakerella/foo.git (fetch)
origin  git@github.com:jakerella/foo.git (push)

Note we can have different URLs for fetching and pushing!

Going Upstream

How do I make a new branch "track" that remote repo?


~/repo$ git checkout -b new-feature
~/repo$ git branch --set-upstream-to=origin/new-feature
        
~/repo$ git push -u origin new-feature
        
~/repo$ git branch -vv
  main              b956c45c [origin/main] Initial commit
* new-feature       b956c45c [origin/new-feature] Initial commit
  some-local-branch a74b2950 Implemented that cool feature

Can there be other remotes?

Assume I've forked the Nodejs main repo...


~$ git clone git@github.com:jakerella/node.git
        
~/node$ git remote -v
origin  git@github.com:jakerella/node.git (fetch)
origin  git@github.com:jakerella/node.git (push)
        
~/node$ git remote add node-source git@github.com:nodejs/node.git
        
~/node$ git remote -v
origin         git@github.com:jakerella/node.git (fetch)
origin         git@github.com:jakerella/node.git (push)
node-source    git@github.com:nodejs/node.git (fetch)
node-source    git@github.com:nodejs/node.git (push)

Open Source Flow

How do I get the latest changes from Nodejs?


~/node$ git fetch node-source
remote: Enumerating objects: 6018, done.
...
From github.com/nodejs/node
 * [new branch] ...
        
~/node$ git checkout main
        
~/node$ git merge node-source/main
Updating 40f7a8ea..a479419b
...
        
~/node$ git checkout new-feature
        
~/node$ git merge main

Branch Differences

We commit some changes to our local feature branch.


~/node$ git diff main new-feature
        
diff --git a/README.md b/README.md
index a479419b..b5a9776f 100644
--- a/README.md
+++ b/README.md
@@ -1 +0,0 @@
-This is a bad line, remove it!
        
diff --git a/feature.js b/feature.js
new file mode 100644
index 0000000..b5a9776f
...

Branch Differences

What if that README change was from another merge?

A diagram of a git repo with a feature branch and divergent change


~$ git diff main new-feature

This is ALL changes between main and new-feature,
(regardless of what branch those came from).

Single-Branch Differences (`..`)


~$ git diff main..new-feature
        
diff --git a/feature.js b/feature.js
new file mode 100644
index 00000000..b5a9776f
--- /dev/null
+++ b/feature.js
...

`..`:	show all commits on "new-feature" not on "main"
`space`:	show all commit differences between "new-feature" and "main"
`...`:	same as `space`

Git and Data Integrity

Git uses snapshots

(versus file diffs)

File Diffs

http://git-scm.com/book/en/Getting-Started-Git-Basics

Snapshots

http://git-scm.com/book/en/Getting-Started-Git-Basics

Commit Hashes


~/repo$ git commit -m "Added documentation"
[main (root-commit) b9bdb026] Added documentation
        
~/repo$ git log
commit b9bdb0261ee9bcaa31d7eb062c0bcafee3e530f0
Author: jdoe <john@doe.com>
Date:   Thu Jan 29 11:27:14 2026 -0400

Added documentation

Local Repos

Every local instance of a git repo has ALL of the data.

That means when GitHub goes down, you keep working...

...even with other people / machines.

A distributued VCS

https://docs.joomla.org/Dvcs

Fixing Changes

Unstaged Changes


~/repo$ echo "testing" >> README.md
        
~/repo$ git status
On branch new-feature
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   README.md

Unstaged Changes


~/repo$ git restore README.md
        
~/repo$ git status
On branch new-feature
nothing to commit, working tree clean

You can also restore entire directories:


~/repo$ git restore source/routes/

Unstaged Changes

Careful, NEW files will not be removed!


~/repo$ echo "testing" > source/routes/new-file.js
            
~/repo$ git restore source/routes/
            
~/repo$ git status
On branch new-feature
Untracked files:
  (use "git add <file>..." to include in what will be committed)
       	sourc/routes/new-file.js

(You can just delete the file if not needed.)

Staged Changes


~/repo$ echo "testing" >> README.md
~/repo$ git add README.md
        
~/repo$ git status
On branch new-feature
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        modified:   README.md
        
~/repo$ git restore --staged README.md
~/repo$ git status
On branch new-feature
Changes not staged for commit:
        modified:   README.md

Remember the Three States!

Fixing Things After Commit

Fixing commit messages


~/repo$ git commit -m "This is teh best"
[feature-branch 54af593b] This is teh best
1 file changed, 1 insertion(+)
    
~/repo$ git commit --amend -m "This is the best"
[feature-branch 0486a7d6] This is the best
1 file changed, 1 insertion(+)

Fixing commit messages


~/repo$ git commit -m "This is teh best"
[feature-branch 54af593b] This is teh best
1 file changed, 1 insertion(+)
        
~/repo$ git commit --amend -m "This is the best"
[feature-branch 0486a7d6] This is the best
1 file changed, 1 insertion(+)

What about the git log?


~/repo$ git log
commit 0486a7d61ee9bcaa31d7eb062c0bcafee3e530f0
Author: jdoe <john@doe.com>
Date:   Thu Jan 29 11:45:14 2026 -0400

This is the best

commit 72267fc26d88fa977d24760252da63b46ca3b81a
Author: fbar <foo@bar.com>
Date:   Wed Jan 28 09:45:10 2026 -0400

Bug fixes for older features

...

What if I forgot a file?

Stage it and amend it.


~/repo$ git add forgotten.js
        
~/repo$ git commit --amend
[new-feature 3e81873b] This is the best
 Date: Thu Jan 29 11:49:54 2026 -0400
 2 files changed, 1 insertion(+), 1 deletion(-)
 create mode 100644 forgotten.js

Caution When Amending!

If you push your bad change,
then amend it,
you might cause a nasty conflict for someone else.

Gone, but not forgotten


~/repo$ git log --oneline
3e81873b (HEAD -> new-feature) This is the best
72267fc2 (origin/main, origin/HEAD, main) Bug fixes for older features
        
~/repo$ git reflog
3e81873b HEAD@{0}: commit (amend): This is the best
0486a7d6 HEAD@{1}: commit (amend): This is the best
54af593b HEAD@{2}: commit: This is teh best.
72267fc2 HEAD@{3}: commit: Bug fixes for older features
...

The reflog is never pushed to a remote.

What if I need to amend an older commit?

You'll need to use git rebase

Interactive Rebasing


~/repo$ git rebase --interactive HEAD^^^


pick 7e10e41c some old commit
pick 72267fc2 Bug fixes for older features
pick 3e81873b This is the best

# Rebase 5a39902..3e81873b onto 5a39902 (3 command(s))
# Commands:
# p, pick <commit> = use commit
# r, reword <commit> = use commit, but edit the commit message
# e, edit <commit> = use commit, but stop for amending
# s, squash <commit> = use commit, but meld into previous commit
# d, drop <commit> = remove commit
...

Interactive Rebasing


~/repo$ git rebase --interactive HEAD^^^


pick 7e10e41c some old commit
edit 72267fc2 Bug fixes for older features
pick 3e81873b This is the best

# Rebase 5a39902..3e81873b onto 5a39902 (3 command(s))
# Commands:
# p, pick <commit> = use commit
# r, reword <commit> = use commit, but edit the commit message
# e, edit <commit> = use commit, but stop for amending
# s, squash <commit> = use commit, but meld into previous commit
# d, drop <commit> = remove commit
...

Interactive Rebasing


~/repo$ git rebase --interactive HEAD^^^
Stopped at 72267fc2... Bug fixes for older features
You can amend the commit now, with
  git commit --amend
Once you are satisfied with your changes, run
  git rebase --continue

Now amend the commit just like before...


~/repo$ git add another-file.js
            
~/repo$ git commit --amend
            
~/repo$ git rebase --continue
Successfully rebased and updated refs/heads/new-feature.

Interactive Rebasing

Careful! You changed all history from that amend forward.


~/repo$ git reflog
7650aafe HEAD@{0}: rebase -i (finish): returning to refs/heads/new-feature
7650aafe HEAD@{1}: rebase -i (pick): This is the best
bcb51f9a HEAD@{2}: commit (amend): Bug fixes for older features
72267fc2 HEAD@{3}: rebase -i: fast-forward
7e10e41c HEAD@{4}: rebase -i (start): checkout HEAD^^^
3e81873b HEAD@{5}: commit (amend): This is the best
0486a7d6 HEAD@{6}: commit (amend): This is the best
54af593b HEAD@{7}: commit This is teh best
72267fc2 HEAD@{8}: commit: Bug fixes for older features
7e10e41c HEAD@{9}: commit: some old commit

Understanding the Three Seashells States

Or... how to use reset for fun and profit.

FYI, reset is the OG restore.
Here's a very helpful StackOverflow answer on the differences.

Understanding the Three States

Understanding the Three States

git reset --soft HEAD^

`HEAD` is just a pointer

In fact, all branch names are just pointers!

And so are tags!

Soft Reset


~/repo$ git reset --soft HEAD^
        
~/repo$ git status
On branch new-feature
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        modified:   README.md

Understanding the Three States

git reset --soft HEAD^

Understanding the Three States

git reset --mixed HEAD^

Mixed Reset


~/repo$ git reset --mixed HEAD^
        
~/repo$ git status
On branch new-feature
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   README.md

Understanding the Three States

git reset --mixed HEAD^

Understanding the Three States

git reset --hard HEAD^

Hard Reset


~/repo$ git reset --hard HEAD^
        
~/repo$ git status
On branch new-feature
nothing to commit, working tree clean

Understanding the Three States

git reset --hard HEAD^

Oh no!

I reset --hard and lost important work!

Git does not remove data easily.

Understanding the reflog


~/repo$ git reflog

b86e65da HEAD@{0}: reset: moving to HEAD^
d42c3864 HEAD@{1}: commit: this is not a good change
b86e65da HEAD@{2}: commit: the immediately previous change (totally normal)
b9bdb02f HEAD@{3}: checkout: moving from main to new-feature
b9bdb02f HEAD@{4}: commit: a really good change
        
~/repo$ git reset --hard HEAD@{1}
HEAD is now at d42c3864 this is not a good change

Understanding the reflog


~/repo$ git reflog
d42c3864 HEAD@{0}: reset: moving to HEAD@{1}
b86e65da HEAD@{1}: reset: moving to HEAD^
d42c3864 HEAD@{2}: commit: this is not a good change
b86e65da HEAD@{3}: commit: the immediately previous change (totally normal)
b9bdb02f HEAD@{4}: checkout: moving from main to new-feature
b9bdb02f HEAD@{5}: commit: a really good change
        
~$ git log --oneline
d42c386 this is not a good change
b86e65d the immediately previous change (totally normal)
b9bdb02 a really good change

HEAD notation

HEAD^ (back one place from current HEAD)
HEAD^^ (back two places from current HEAD)
HEAD~n (back 'n' places from current HEAD)
HEAD@{i} (back to reflog index 'i')

Logs

http://thedailyomnivore.net/2012/02/20/ren-stimpy/

The Basic Log


~/repo$ git log
commit d42c38691161f42fcc07d806f7df4579e8cd189e
Author: jakerella <me@example.com>
Date:   Fri Jan 30 13:57:36 2026 -0400

Added new API route to readme docs

commit b9bdb0261ee9bcaa31d7eb062c0bcafee3e530f0
Author: jakerella <me@example.com>
Date:   Thu Jan 29 09:14:16 2026 -0400

Various grammar edits to documentation

Log Options


~/repo$ git log --oneline

d42c3869 Added new API route to readme docs
b9bdb026 Various grammar edits to documentation
c2cb87e3 Remove unused files from test harness
2e8a119c Merge pull request #186 from jakerella/new-feature
79eec03a Reorganized documentation sections and renamed
...

Formatting and Graphing


~/repo$ git log --pretty="tformat:%h %as %an: %s" --graph
    
* 714e0dd9 2026-01-30 jakerella: Merge pull request #220 from foobar/feature-two
|\
| * c8bcfc14 2026-01-29 roro: last update for feature two
| * 3e3a8fdf 2026-01-28 jakerella: Merge branch 'feature-two-tweak' into feature-two
| |\
| | * 46f4cf12 2026-01-28 drnick: tweak for feature two
| * | 1471f2b8 2026-01-27 drnick: one more thing on feature two
| |/
| * 5ce150bc 2026-01-26 drnick: feature two initial work
|/
* 062b1f01 2026-01-25 roro: some previous work

Make it Easy

Add an alias to your bash or gitbash profile:


alias gl="git log --pretty='tformat:%h %as %an: %s' --graph"

Filtering the Log


~/repo$ git log --no-merges

~/repo$ git log --author="jakerella"

~/repo$ git log --before="2026-02-01"

~/repo$ git log -- source/routes

~/repo$ git log --grep=4\.31\.[0-9]+ -E

Playing Nice With Others

merge, rebase, and cherry-pick

Merging

With no divergent changes...

Fast Forward

With no divergent changes... we can "fast forward"


~/repo$ git checkout main
~/repo$ git merge feature


Updating b86e65d..d42c386
Fast forward
source/some-file.js |   13 ++++--+++
1 files changed, 7 insertions(+), 2 deletions(-)

Merging

With fast forward...

Merging

With fast forward...

No Fast Forward


~/repo$ git checkout main
~/repo$ git merge feature --no-ff

No Fast Forward


~/repo$ git log --oneline

d42c3869 Added new API route to readme docs
b9bdb026 Various grammar edits to documentation
c2cb87e3 Remove unused files from test harness
3e3a8fdf Merge branch 'feature-two-tweak' into feature-two
79eec03a Reorganized documentation sections and renamed
...

Divergent Changes

When code in feature diverges from the current trunk...


~/repo$ git checkout main
~/repo$ git merge feature

Divergent Changes

When code in feature diverges from the current trunk...


~/repo$ git checkout main
~/repo$ git merge feature

Divergent Changes

When code in feature diverges from the current trunk...


~/repo$ git checkout main
~/repo$ git merge feature

Divergent Changes

When code in feature diverges from the current trunk...


~/repo$ git log --oneline
c345d92 Merge branch 'feature' into main
d42c386 Added new-feature to library
7a652d8 A piece of divergent work
b86e65d Some older work

Merge Conflicts

Conflicts

Git can't resolve multiple changes to the same lines.


~/repo$ git checkout main
~/repo$ git merge new-feature

Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Automatic merge failed; fix conflicts and then commit the result.

Resolving the Conflict

Fix the conflict in the file!
Stage the fixed file
~$ git add README.md
Commit the files
(This is your merge commit, it may include other files!)
~$ git commit

Conflicts

Opening up the README.md file...


...some text common to both branches

<<<<<<< HEAD
text only in main
=======
same line, different text in branch
>>>>>>> new-feature

more common text...

Resolving the Conflict

Struggling to resolve the conflict?


~/repo$ git merge --abort

Abort and ask for help!

Rebasing

Rebasing rewrites commit history!

Divergent Changes

Rewriting History

git rebase diagram with rewritten branch commits


~/repo$ git checkout feature
~/repo$ git rebase main

Updating Main

We can update main with a fast-forward merge.

git rebase diagram with rewritten commits on main


~/repo$ git checkout main
~/repo$ git merge feature

You can still get conflicts with `rebase`!

Rebase Conflicts


~/repo$ git rebase main

First, rewinding head to replay your work on top of it...
Applying: feature
error: patch failed: README.md:1
error: README.md: patch does not apply
Using index info to reconstruct a base tree...
Falling back to patching base and 3-way merge...
Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Failed to merge in the changes.

Resolving the Conflict

Fix the conflict in the file!
Stage the fixed file
~$ git add README.md
Commit the fix
~$ git commit
Continue the rebase
~$ git rebase --continue

Not going well?

You can abort the rebase just like a merge:


~/repo$ git rebase --abort

Use GitHub? No problem.

A screenshot of GitHubs Pull Request screen using rebase versus merge.

A Recommendation...

If you plan to use rebase versus merge, always use rebase.


~/repo$ git pull
        
~/repo$ git fetch && git merge
        
~/repo$ git pull --rebase
        
~$ git config branch.main.rebase true
~$ git config branch.autosetuprebase always

Cherry-picking

Cherry Pick


{{just spacing}}
{{just spacing}}

Cherry Pick


~/repo$ git checkout new-feature
~/repo$ git cherry-pick d42c386

Cherry Pick


        ~$ git branch -D old-feature

Cherry Pick

Yes, you can still get conflicts with a cherry-pick!

Don't keep that old branch around!

Thank You!