Changes rolled back immediately after commit

[roma86]

Hello. Thank you for this library.

I can not find solution via google for next problem:

After Rugged::Commit.create changes rolled back immediately.

I have create test method and test repository

Try write changes to existing file 'index.md'

def create_commit
  repo = Rugged::Repository.new('TB 2')
  puts 'Init repository'
  puts '. . . . . . . . . . . .'

  changes = "- - - - - - \n test blob"

  oid = repo.write(changes, :blob)
  index = repo.index
  index.read_tree(repo.head.target.tree)
  index.add(:path => 'index.md', :oid => oid, :mode => 0100644)

  author = {:email => 'current_user.email', :time=>Time.now, :name => 'current_user.email'}
  options = {}
  options[:tree] = index.write_tree(repo)

  options[:author] = author
  options[:committer] = author
  options[:message] ||= "Edit page test"
  options[:parents] = repo.empty? ? [] : [ repo.head.target ].compact
  options[:update_ref] = 'HEAD'

  commit_result = Rugged::Commit.create(repo, options)
  puts commit_result.inspect

  puts '. . . . . . . . . . . . <'
end

Repository before changes:

Execute method:

$ irb
> load './rugged_test.rb'
=> true

> create_commit
. . . . . . . . . . . .
"0e7891687e9aa0a3868c29046dbd033767ae2aca"
. . . . . . . . . . . . <
=> nil

Repository after changes:

---

Rugged version:

    ...

    Installing rugged 0.21.4

    ...

I am not good know git itself, but use instructions from Rugged Readme page. Looks like i have missing some additional step in setup or commit, but i can not figure out which of.

[carlosmn]

You are not storing the changes you have done to the index back to disk. Add index.write() after changing the contents of your in-memory index so the updated information is written back to the index file and git knows what you meant to do.

[roma86]

@carlosmn thank you for answer.
How you know this? Is it git specific? Just want to find docs or something to understand all this possibilities of rugged. In my code already used index.write_tree(repo) and without instructions one more index.write looks redundant, I could not come to this decision logically.