title: the modified file pulled through git pull origin master is not shown as changed even though git log confirms the pull
body: <p>I have a branch and wanted to git the changes in the master using $ git pull origin master
  After I do this, the pull really didn't show any merged PR being pulled and said it's already updated. However, the git log shows the last merged PR.</p>
  <p>So how can I get the latest changes (a merged PR) on this branch?</p>
  <p>Doing the $ git pull origin master on the master branch shows the merged PR being pulled.</p>
  <p>How can I fix this problem? Since the README.md that I have merged its PR on the Github page, and also was able to use git pull origin master and pull it to master is not being pulled into this new branch.</p>
  <pre><code>$ git branch
    dataprocessing
    master
  * toyota
  </code></pre>
  <p>When in the branch:</p>
  <pre><code>$ git merge master
  Already up to date.
  </code></pre>
  <p>and</p>
  <pre><code>$ git branch -vv
    dataprocessing dcaa9f9 Merge pull request #122 from XYZaiXYZ/toyota
    master         dcaa9f9 [origin/master] Merge pull request #122 from XYZaiXYZ/toyota
  * toyota         dcaa9f9 [origin/toyota: ahead 1] Merge pull request #122 from XYZaiXYZ/toyota
  </code></pre>
  <p>Additionally, the following yields no results:</p>
  <pre><code>$ git diff origin master
  </code></pre>
  <p>This is what I see in the README.md in local branch toyota:
  <a href="https://i.stack.imgur.com/LUcQf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LUcQf.png" alt="enter image description here" /></a></p>
  <p>This is what I see in the README.md in GitHub PR which I merged:
  <a href="https://i.stack.imgur.com/NLnAW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NLnAW.png" alt="enter image description here" /></a></p>
  <p>This is what I see when I browse to the actual README.md in GitHub website:
  <a href="https://i.stack.imgur.com/8VcSy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8VcSy.png" alt="enter image description here" /></a></p>
  <p>This is what I see if I $ git checkout master, as you see even in master after pulled update the README.md is not changed:
  <a href="https://i.stack.imgur.com/8ghAb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8ghAb.png" alt="enter image description here" /></a></p>
  <pre><code>$ git checkout toyota
  Switched to branch 'toyota'
  Your branch is ahead of 'origin/toyota' by 1 commit.
    (use &quot;git push&quot; to publish your local commits)
  
  $ git merge origin master
  Already up to date.
  
  $ git log README.md 
  commit ac7cXXXX (origin/toyota)
  Author: Mona Jalal &lt;mona@XYZ&gt;
  Date:   Fri Feb 5 22:40:32 2021 +0000
  
      fixed two typos in the README.md
  
  $ git pull origin master
  From ssh://github.com/XYZaiXYZ/vision
   * branch            master     -&gt; FETCH_HEAD
  Already up to date.
  </code></pre>
  <p>I have merged #122 PR to master myself and I see this when I enter the git repo:
  <a href="https://i.stack.imgur.com/k2Rsx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/k2Rsx.png" alt="enter image description here" /></a></p>
  <pre><code>$ git checkout master
  $ git log
  commit dcaa9XYZ (HEAD -&gt; master, origin/master, origin/HEAD, toyota, dataprocessing)
  Merge: 3b29485 ac7c61e
  Author: Mona Jalal &lt;76495162+XYZ@users.noreply.github.com&gt;
  Date:   Fri Feb 5 17:44:36 2021 -0500
  
      Merge pull request #122 from XYZaiXYZ/toyota
      
      fixed two typos in the README.md
  </code></pre>
  <p>I also did git clone the repo in a test dir and I can see the changes are shown in this new clone
  <a href="https://i.stack.imgur.com/1KtKG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1KtKG.png" alt="enter image description here" /></a></p>