chart_copy() does not work correctly

The code for chart_copy() looks good.

I cannot apply the code change to chart_url() since it will cause problems for non-HTTPS sites. Is there an issue with that code?

-    return url('//' . $uri, array('query' => $data, 'external' => TRUE));
+    return url('https://' . $uri, array('query' => $data, 'external' => TRUE));

If that is the case, it is a separate problem and should have a separate issue. Both HTTP and HTTPS work with Google Image Charts:

• http://chart.googleapis.com/chart?cht=p3&chd=s:Uf9a&chs=250x100&chl=January|February|March|April
• https://chart.googleapis.com/chart?cht=p3&chd=s:Uf9a&chs=250x100&chl=January|February|March|April

Can you show me an example where url('//'); doesn't work? I've had no problem with it.

Ah... Only there. Interesting it doesn't affect anything else. The ideal method to correct this is to detect what the current page is loading as and adjust the protocol accordingly.

Please review this previous issue regarding HTTPS vs HTTP for chart: #587742: Use protocol relative Google Chart API URL. The code requires an isset() at the minimum.

I fixed the whitespace errors and committed.

chart-copy-issue-1303706-comment-13.patch:38: trailing whitespace.
      return FALSE;      
chart-copy-issue-1303706-comment-13.patch:41: trailing whitespace.
    
chart-copy-issue-1303706-comment-13.patch:47: trailing whitespace.
    else { 
chart-copy-issue-1303706-comment-13.patch:50: trailing whitespace.
    
chart-copy-issue-1303706-comment-13.patch:63: trailing whitespace.
    return $filename;      
warning: 5 lines add whitespace errors.