RE: git merge deletes my changes

[Eduard Egorov <Eduard.Egorov@icl-services.com>]

Hello again,

I've noticed that my git is quite old (1.8.3) and built it from source tarball (2.10.1). Now the output is:

# ~/gitbuild/git-2.10.1/git merge -s subtree --squash ceph_ansible
fatal: refusing to merge unrelated histories

I've checked my command history again:
  738  git rm -rf ceph-ansible/
  739  ll
  740  ll ceph-ansible/
  741  rm ceph-ansible/purge_ceph_cluster.yml 
  742  git read-tree --prefix=ceph-ansible/ -u ceph_ansible
  743  gs
  744  gc "ceph-ansible: reset repo state"

A quick googling showed (http://stackoverflow.com/questions/37937984/git-refusing-to-merge-unrelated-histories ) that the default behavior is changed. Adding ' --allow-unrelated-histories' clears the error message but the merge itself is still wrong (my changes are lost). 

This error message might explain why git can't merge it correctly (since these repos doesn't has any relations, right). Can somebody confirm this please? Doesn't "merge -s subtree" really merges branches?

With best regards
Eduard Egorov

-----Original Message-----
From: Eduard Egorov 
Sent: Monday, October 10, 2016 12:39 PM
To: 'git@vger.kernel.org' <git@vger.kernel.org>
Subject: git merge deletes my changes

Hello Git experts,

A week ago, I've reset a state of 'ceph-ansible' folder in %current% branch with code from corresponding branch (that tracks an upstream from github):

# git read-tree --prefix=ceph-ansible/ -u ceph_ansible

Then I've committed several changes, including:

1. Renamed file and commited:
# git mv site.yml.sample site.yml

2. Made some changes and committed

3. Pulled updates from original branch by:
# git merge -s subtree --squash ceph_ansible

It said:
    Auto-merging ceph-ansible/site.yml.sample
    blablabla
    Squash commit -- not updating HEAD
    Automatic merge went well; stopped before committing as requested

I can see that "my" ceph-ansible/site.yml is deleted (as well as few new files added by me), ceph-ansible/site.yml.sample is restored and doesn't contain my changes (it's just restored to the state before my changes).
`git log ceph_ansible site.yml.sample` shows the latest change on ceph_ansible branch done from 26th of August, 2016, my changes in %current% branch was this October, so it shouldn't be any conflict either (even if it was).
I believe there is some obvious explanation for this behavior. Could you help me please? What information can  I provide in order to troubleshoot this issue? 

A post on SO: http://stackoverflow.com/questions/39954265/git-merge-deletes-my-changes

With best regards
Eduard Egorov