title: After I rebase and then sync, history doubles in the PR and shows unrelated changes
body: <p>I've asked this question poorly earlier today, now that I tried a few more things I may have a better understanding.</p>
  <p>Situation:</p>
  <ul>
  <li>I've a fork of F#</li>
  <li>I've a local <code>master</code> and a local <code>workbranch</code> and both are also in my fork.</li>
  <li>There a PR of the workbranch</li>
  <li>Workbranch has 7 files changed</li>
  <li>A PR was merged into upstream master that is useful to my own work, so I want to rebase my branch</li>
  <li>My workbranch is 1 commit behind master. I want that last commit, which has 26 changed files</li>
  <li>I like to see my changes as-if after the head of master (hence: rebase)</li>
  </ul>
  <p>The commands I did:</p>
  <pre><code>git checkout master
  git fetch upstream
  git merge upstream/master
  git push origin/master
  
  git checkout workbranch // up-to-date with origin
  git rebase master
  git rebase --continue   // after solving merge conflict
  git pull .    // not sure why there were changes to be pulled, was this where I went wrong?
  git push .
  </code></pre>
  <p>After this, the result was that I see:</p>
  <ul>
  <li>21 commits of earlier today</li>
  <li>1 commit from master with those 26 changed files</li>
  <li>another 8 commits that are exactly equal to some of the earlier 21 commits</li>
  <li>a merge commit of this rebase</li>
  <li>the diff shows 33 files changed</li>
  </ul>
  <p>In the branch-comparison overview on github.com, in my fork, I see:</p>
  <ul>
  <li>21 commits of earlier today</li>
  <li>another 8 commits like above</li>
  <li>the merge commit of the rebase</li>
  <li>the diff here shows 7 files changed</li>
  </ul>
  <p>What I expected to see is <strong>my original commits, each only once, not duplicated, the merge-commit, and there should be no commit from master</strong>.</p>
  <p>I suspect it has something to do with the pull-before-push.</p>