title: How to fix "modified content, untracked content" in git?
body: <p><strong>The objective is to commit a git branch. The output of "git status" for the branch is:</strong></p>
  
  <pre><code>On branch zeromq_new
  Your branch is up to date with 'origin/zeromq'.
  
  Changes not staged for commit:
    (use "git add &lt;file&gt;..." to update what will be committed)
    (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
    (commit or discard the untracked or modified content in submodules)
  
        modified:   log4cplus (modified content, untracked content)
        modified:   ../lib/notification/cppzmq (modified content)
  </code></pre>
  
  <p>The directory structure looks like this:</p>
  
  <pre><code>HySecureGateway
  ├──fes
  │   └──log4cplus
  │       ├──.git
  │       ├──.gitattributes
  │       ├──.gitignore
  │       ├──.gitmodules
  │       ├──catch
  │       │   ├──.git
  │       │   ├──.gitattributes
  │       │   ├──.github
  │       │   ├──.gitignore
  │       │   └──.github
  │       │       ├──issue_template.md
  │       │       └──pull_request_template.md
  │       └──threadpool
  │           └──.github
  └──lib
      └──notification
          └──cppzmq
              ├──.git
              └──.gitignore
  </code></pre>
  
  <p>I read an answer of to a similar question here: </p>
  
  <p><a href="https://stackoverflow.com/questions/4161022/how-to-track-untracked-content?utm_medium=organic&amp;utm_source=google_rich_qa&amp;utm_campaign=google_rich_qa">How to track untracked content?</a> , </p>
  
  <p>and couldn't understand it completely. 
  Also the logc4plus/.gitmodules contains this:</p>
  
  <pre><code>[submodule "threadpool"]
  
          path = threadpool
          url = https://github.com/log4cplus/ThreadPool.git
  
  [submodule "catch"]
  
          path = catch
          url = https://github.com/philsquared/Catch.git
  </code></pre>