rn-35: add svn to git article

Author: chriscool

rev_news/drafts/edition-35.md

@@ -25,9 +25,78 @@ This edition covers what happened during the month of December 2017.
 ### Reviews
 -->
 
-<!---
 ### Support
--->
+
+*[Need help migrating workflow from svn to git](https://public-inbox.org/git/[email protected]/)
+
+Josef Wolf first described is current workflow that uses Subversion
+(SVN).
+
+Josef has a number of machines that all have a working copy of the
+same repository in a specific directory. A cron job updates the
+working copies and then run scripts contained in the working copies.
+
+When using `svn updates` to update those copies, the changes made
+locally on the machines are automatically merged with the upstream
+changes usually without conflict.
+
+Then Josef explained what would happen with Git:
+
+> With git, by contrast, this won't work. Git will refuse to pull
+> anything as long as there are ANY local modifications. The cron job
+> would need to
+>
+>  git stash
+>  git pull
+>  git stash pop
+>
+> But this will temporarily remove my local modifications. If I happen
+> to do a test run at this time, the test run would NOT contain the
+> local modifications which I was about to test.
+
+Randall S. Becker suggested using `git fetch` instead of `git pull` to
+be able to first tell if changes from upstream have to be applied to
+the local copy, and also using a branch for each machine to better
+track local changes and merge them with upstream changes.
+
+Josef replied to Randall by asking for a way to "properly check
+whether a merge is actually needed" as it looks like `git status` or
+`git diff` are not very well suited for that purpose.
+
+Igor Djordjevic, alias Buga, wondered about the possibility, in the
+original workflow, of running scripts that are being worked on. Buga
+also said that using `git stash` would probably have other issues, so
+he suggested the "(scripted) creation of a temporary branch at fetched
+remote branch position, and using something like
+`git checkout --merge <temp_branch>` to merge ... local modifications
+to latest changes fetched from remote".
+
+In a later email Buga alternatively suggested "using
+`git worktree add <temp_copy_path>` to create a temporary working tree
+... alongside a temporary branch" and deleting those after having
+commited, merged and pushed the local changes made there.
+
+Josef replied to Buga that some potential issues Buga worried about
+are not relevant when using SVN because of the specifics of his work,
+while others are indeed relevant when using Git.
+
+About the solutions Buga had suggested, Josef and Buga started to
+discuss them, but at this point Junio Hamano, the Git maintainer,
+suggested using just:
+
+> git fetch <remote> <branch>
+> git checkout -m -B <master> FETCH_HEAD
+
+with:
+
+> <remote> <branch>: the branch at the remote you are pulling from
+> <master>: whatever branch you are using
+
+After some tests and further discussion, Josef agreed that it was a
+good solution. Buga also suggested using `git add -u` and `git reset`
+after or before the above commands to avoid failures in case the
+script runs many times and there are conflicts.
+
 
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 ## Developer Spotlight: