title: Arrange a grouped_df by group variable not working
body: <p>I have a data.frame that contains client names, years, and several revenue numbers from each year.</p>
  
  <pre><code>df &lt;- data.frame(client = rep(c("Client A","Client B", "Client C"),3), 
                   year = rep(c(2014,2013,2012), each=3), 
                   rev = rep(c(10,20,30),3)
                  )
  </code></pre>
  
  <p>I want to end up with a data.frame that aggregates the revenue by client and year. I then want to sort the data.frame by year then by descending revenue.</p>
  
  <pre><code>library(dplyr)
  df1 &lt;- df %&gt;% 
          group_by(client, year) %&gt;%
          summarise(tot = sum(rev)) %&gt;%
          arrange(year, desc(tot))
  </code></pre>
  
  <p>However, when using the code above the <code>arrange()</code> function doesn't change the order of the grouped data.frame at all.  When I run the below code and coerce to a normal data.frame it works.</p>
  
  <pre><code>   library(dplyr)
      df1 &lt;- df %&gt;% 
              group_by(client, year) %&gt;%
              summarise(tot = sum(rev)) %&gt;%
              data.frame() %&gt;%
              arrange(year, desc(tot))
  </code></pre>
  
  <p>Am I missing something or will I need to do this every time when trying to <code>arrange</code> a grouped_df by a grouped variable?</p>
  
  <p>R Version: 3.1.1
  dplyr package version: 0.3.0.2</p>
  
  <p><strong>EDIT 11/13/2017:</strong>
  As noted by <a href="https://stackoverflow.com/users/1177738/lucacerone">lucacerone</a>, beginning with dplyr 0.5, arrange once again ignores groups when sorting.  So my original code now works in the way I initially expected it would.</p>
  
  <blockquote>
    <p>arrange() once again ignores grouping, reverting back to the behaviour of dplyr 0.3 and earlier. This makes arrange() inconsistent with other dplyr verbs, but I think this behaviour is generally more useful. Regardless, it’s not going to change again, as more changes will just cause more confusion.</p>
  </blockquote>