Git merge with overwriting local changes [duplicate] - git-merge

In Git, during a merge, is there a way that we can tell git to discard local changes in case of a conflict and apply the changes from the merged branch?
I mean if there is a way, then we can do merges like branch merges without conflicts.

Before trying to merge, you can discard the local changes yourself git reset --hard HEAD.
You can replace HEAD by whatever commit hash you want.
This will bring you the the clean state of the commit you're actually on, and you'd lose all your changes.
If you want to keep them, you can stash them before with git stash, or move them to another branch:
git checkout -b new_branch
git add .
git commit -m "My awesome commit"
git checkout - # will bring you back to the last branch you were in

If you want to ignore all local changes, and an additional merge commit you want to just move your branch to the remote HEAD.
git log --oneline origin/master
# assume the first sha is bbdfa17
git reset --hard bbdfa17
Now you are at the tip of the tree with no merge commits.

It sounds like you want to read about the merge strategies 'theirs' and 'ours'. When merging you can specify that either your current branch (ours) or the remote branch (theirs) is the correct one.

Related

Best way to clone a github repository

Ok so here's the scenario.
I made a pretty bad newbie mistake. I was working on some code and didn't create a dev branch to checkout and test in development. So I've made all of these changes to the master branch on my machine that are still broken (in development) and my boss wants me to make some changes to the app in production.
My thoughts on how to do this was:
Rename my project's directory so I have a backup of it
git clone the last remote version back onto my machine
Make the slight changes he wants and re-deploy/commit
Sort out what I've changed in my old version of the app and bring it into a dev branch into the newly cloned master branch.
Any thoughts on this? I really don't want to screw up production right now and I've made too many changes to keep track of to revert to where the code was stable.
No need to go through that much trouble:
git checkout master # get the 'bad' version
git branch bad-master # make a new branch called 'bad-master', cut off master's current state
git fetch # make sure you're up to date with the remote
git reset --hard origin/master # reset your master branch to origin/master's state
<work work work>
git checkout bad-master # when you're ready to work on bad-master again
Note that git reset --hard origin/master will discard any work in your working tree that you haven't checked in... so if you've got work you haven't committed yet, be sure to git stash it.
This is a completely normal situation to wind up in, and one you can easily recover from.
All you need to do is:
Create a new branch pointing to your current version of master
git checkout -b my-feature-branch
Reset your master to the same thing as origin/master
git checkout master
git reset --hard origin/master
That's it. Now your master is the same as it was before you did your feature development, and you have a feature branch set aside which you can later checkout to resume development.

How do I change ignore-paths on an existing git-svn repo?

I have an already existing git-svn repo with an ignore paths in my .config file that looks like this:
ignore-paths = ^(?!(Path1/Proj1|Path1/Proj2|Path2/Proj3))
This works well.
Someone added a new project in svn that I now need in my git repo.
If I change ignore-paths to what's below and issue a fetch or a rebase, I never see Path2/Proj4
ignore-paths = ^(?!(Path1/Proj1|Path1/Proj2|Path2/Proj3|Path2/Proj4))
In the past, I've always given up and blasted away my git repo and recreated it. Is there a better way?
After editing the ignore-paths you need to
git svn reset -r <n> -p # where <n> is the SVN revision where the new path was added.
git svn fetch
git rebase # or reset
Reference git-svn(1):
reset
Undoes the effects of fetch back to the specified revision.
This allows you to re-fetch an SVN revision. Normally the
contents of an SVN revision should never change and reset
should not be necessary. However, if SVN permissions change,
or if you alter your --ignore-paths option, a fetch may fail
with "not found in commit" (file not previously visible) or
"checksum mismatch" (missed a modification). If the problem
file cannot be ignored forever (with --ignore-paths) the only
way to repair the repo is to use reset.
Only the rev_map and refs/remotes/git-svn are changed (see
$GIT_DIR/svn/*\*/.rev_map.* in the FILES section below for details).
Follow reset with a fetch and then git reset or git rebase to
move local branches onto the new tree.

Commit git-svn changes to SVN repo

we have a central SVN repo in our company. I use git-svn on my laptop to be able to use a repo, when I'm not connected to the company network.
Now I was 3 weeks on a business trip and committed a lot to my local Git repo. There were also many commits to the SVN repo.
When I try "SVN Rebase" I have to edit conflicts in each of my Git changesets. What I would like to do is just to commit all of my local changes at once and then edit conflicts only once.
I'm fairly new to Git, so I don't know how this is done properly and if this is the best way.
I use TortoiseGit on Windows, so up to now I didn't really care about the command line.
Thanks for your help.
Once you go through conflict resolution in git-svn rebase once you are in a new tree with new commits that include your resolutions. A future git-svn rebase will not encounter the same problems (unlike repeated merges, which is where rerere comes in handy).
If by "commit all my local changes at once" you mean you want to fold all of your commits into a single commit in git (and later SVN) then you can use git rebase -i to "squash" all of your commits into a single commit. You should not include any revisions that have already been sent to SVN with dcommit in that rebase -i because you are rewriting history. You will still have to resolve conflicts when you git-svn rebase just like you would if you were using only SVN and did svn update.

How to recover from an unwanted rename using git-svn: "Transaction is out of date"

I'm using git-svn. I've moved file 'A' to 'B' and I'm up to date with the svn HEAD (using git svn rebase). I can commit all other changes without problems. Now I've decided that I want to move 'B' back to 'A' and commit that change.
When I do the move and commit to my local master it works fine, but I get the following when doing a git svn dcommit:
Transaction is out of date: Out of date: 'A' in transaction '3652-1' at /opt/local/libexec/git-core/git-svn line 570
So I tried to copy and delete in a separate commit which resulted in:
Item already exists in filesystem: File already exists: filesystem '/usr/svn/db', transaction '3652-1', path 'A' at /opt/local/libexec/git-core/git-svn line 4735
I've recovered from this situation with plain svn by using the workarounds like the one described in the documentation, but I don't know how to recover with git-svn. What is going on and how do I fix it?
Removing .git/svn did not work for me. Instead, here's how I resolved:
Deleted the offending directories from the repository (But I'm not sure that this is necessary. In hindsight I think I could have skipped this step)
git svn rebase
During the rebase, there were some conflicts. For each conflict, I resolved the conflicts in text editor, then used git add <file-in-conflict> and then git rebase --continue
After rebase completed successfully, git svn dcommit ran successfully!
I can't claim to understand what's really going on under the hood in git-svn in this case (although the underlying SVN issue makes perfect sense). My usual strategy when git-svn gets confused somehow is to blow away the .git/svn metadata directory (as in this post). This almost always saves me from odd synchronization issues between the git and SVN repositories.
It happened with me when I interrupted the dcommit process.
Follow these steps to recover from error:
git svn rebase
You will get conflicts in files. Resolve the conflicts & then git add filename (in which conflict occurred) for each file.
Now do git svn dcommit. It will be pushed to remote successfully.

How to dcommit only selected patches with git svn?

I have a number of locally committed patches in my git-svn repo which I haven't yet commited to our svn repo. A normal "git svn dcommit" will commit all of these patches to svn. I would like to commit only some of my patches (simple bug fixes), but not others (untested major changes). How can I do this with git svn?
I've been following the procedure here:
http://fredericiana.com/2009/12/31/partial-svn-dcommit-with-git/
If you're comfortable rebasing, it works pretty well.
Here's what I ended up doing. The starting point is the "master" branch synced with svn, with all of my local patches on top.
Create a new branch (wip = Work In Progress).
git branch wip
This makes a copy of the current branch, including all patches not yet committed to svn. The current branch will stay as "master" and will not be changed.
Remove the unwanted local patches from "master" with a rebase:
git rebase -i HEAD~10
Now the "master" branch has patches you can safely commit:
git svn dcommit
The "wip" branch now has the major changes which aren't yet ready for sharing. Actually, I want them to stay there and this is where I would stop. It's possible to do the svn dcommit from the "wip" branch once everything is finalized. But for completess' sake, and to answer the original question, there's a final step:
Pull the uncommitted changes back to the "master" branch using git cherry-pick and finally remove the useless branch with git branch -d wip.
With git, you're not actually supposed to operate on single changesets. The best approach I know is to create local branches for any non-trivial work. This way, your untested major changes will end up in different branches of your git repository, and you'll be able to differ them quite easily.
If this is the problem you have at the moment you can probably create create a new branch from the point you last updated from svn and then use git-cherry-pick to transfer your simple bug fixes to this new branch, from which you can then dcommit to svn.
From a more long-term point of view it's best to have your own "master" branch made from subversion trunk, and then either:
Rebase all your branches every time you update from svn, then merge those you want to get to svn to your master and dcommit from there.
Merge stuff from svn using regular git-merge, and then merge stuff to your master for dcommits by git diff ..my_branch | patch -p1, which will eliminate history that git-svn can't handle. This approach is more complicated for the final merging but allows you to merge stuff between branches (and possibly other people) in git itself.