On Tue, Sep 5, 2017 at 5:53 PM, Daniel Biran <dbiran@xxxxxxxxxx> wrote:
>
>>> I'm trying to better understand one of the merge algorithms as I had some triumphs and tribulations with using a set of commands during a merge. tldr: can a git merge -s recursive -X patience; // result in a fast-forward merge? will --no-ff stop it
>>>
>>> So, the scenario is this:
>>> - Merging a master branch into a feature branch that is 2+ years old
>>> - We found this command was more beneficial when merging a large 20k line text file:
>>> - git merge -s recursive -X patience master
>>> - In a recent merge using this approach the reflog shows that the merge was performed using a fast-forward from the feature branch's head
>>> - 082517-1, feature/branch) HEAD@{23}: merge feature/branch: Fast-forward
>>>
>>>
>>> My question is, is it possible for that command to use a fast-forward like this? (or did something else go horribly wrong? possibly an atlassian git GUI tool corrupting the work):
>>> - If it is possible for the command to fast-forward the merge when making the commit does --no-ff force the command to never use fast-forward in this case
Unless you specify --no-ff, git merge is always free to create a
fast-forward "merge", even when you request the recursive strategy
explicitly:
$ git init recursive-merge
Initialized empty Git repository in C:/Temp/recursive-merge/.git/
$ cd recursive-merge/
$ echo "Test" > file.txt
$ git add file.txt
$ git commit -m "Initial commit"
[master (root-commit) ad48617] Initial commit
1 file changed, 1 insertion(+)
create mode 100644 file.txt
$ git checkout -b feature-branch
Switched to a new branch 'feature-branch'
$ echo "Edit" >> file.txt
$ git commit -am "Feature branch change"
[feature-branch b226557] Feature branch change
1 file changed, 1 insertion(+)
$ git checkout master
Switched to branch 'master'
$ git merge -s recursive -X patience feature-branch
Updating ad48617..b226557
Fast-forward
file.txt | 1 +
1 file changed, 1 insertion(+)
With --no-ff:
$ git reset --hard ad48617
HEAD is now at ad48617 Initial commit
$ git merge --no-ff -s recursive -X patience feature-branch
Merge made by the 'recursive' strategy.
file.txt | 1 +
1 file changed, 1 insertion(+)
With fast-forwarding disabled, you can see the recursive strategy is
used as requested.
>>>
>>> Thanks for the help,
>>> Daniel
>>
>
