title: git will not merge - says 'Already up-to-date.' when it's not
body: <p>I have a git issue I've never encountered before. </p>
  
  <p>I have 2 branches that have 2 files that differ.<br>
  If I merge one into the other (in either direction) it says 'Already up-to-date.' </p>
  
  <p>Why does it think they are up to date, and how can I get it to merge? </p>
  
  <p>I read this post <a href="https://stackoverflow.com/questions/7746325/git-merge-does-not-merge">git merge does not merge</a> (and others) and they all say "If it says up to date then you have merged correctly." </p>
  
  <p>I realize git <em>thinks</em> they are merged, but they are not - I have files in the 2 branches that differ. </p>
  
  <p>Even if I go in and make changes and I merge it still says 'Already up-to-date.'</p>
  
  <p>Can I get git to "forget" I have merged them and it to merge again?</p>
  
  <p>I don't know what happened to get in this state, but it's been a nightmare.   There must be some way to fix this. </p>
  
  <p>Update with what I did:</p>
  
  <p>I am the only one working on this. I was asked to add some new features so I made a branch off master, new_features, and started work on them. Then I was told to put that aside and work on higher priority new features, so I made another branch off master, new_features2, and I started working on those. Then I was told we needed some bug_fixes, and I made another branch off master, bug_fixes. I fixed the bugs and merged bug_fixes into master. Then I went back to working new_features2, got that stuff working, merged master into new_features2, tested, then merged new_features2 into master. All good so far. </p>
  
  <p>Now I'm back to working in new_features. I get that stuff done, and merge master into new_features. It does merge some stuff. I test, and I find that neither the new_features2 stuff nor the bug_fixes are working quite right. I look at the merged code and it seems some of the changes from new_features2 and bug_fixes are in new_features, but not all of them. I try to merge again - it says "Already up-to-date."</p>