wfx range-type='new' doesn't reset last downloaded sid

Setting to `Needs review` to trigger travis.

I applied this patch and tested the drush wfx --range-type='new' command. Works as expected with only new results being exported.

I did not test through the Drupal UI.

I took a quick look and see one minor style issue and a bug:

1. +++ b/includes/webform.report.inc
   @@ -1330,6 +1315,9 @@ function webform_results_batch_headers($node, $format = 'delimited', $options =
   +  global $user;
   

   This is an anti-pattern. You can easily screw yourself with a global $user. I've been converting these to $GLOBALS['user'] as I work on issues.

2. +++ b/includes/webform.report.inc
   @@ -1380,6 +1368,21 @@ function webform_results_batch_rows($node, $format = 'delimited', $options = arr
   +  if ($context['finished'] && !in_array($options['range']['range_type'], array('range', 'range_serial', 'range_date')) && !empty($context['results']['last_sid'])) {
   

   Not quite. You are evaluating a floating point number as a boolean. The truthy value of 0.5 is TRUE, so this will do the db_merge part way through the batch. To test this, set the batch size small enough that multiple batches are exported.

This needs testing with both drush and the UI. It also needs testing with multiple batches.

Oh, also, thanks for the am-style patch. However, you need to put a Drupal and webform standard commit message in it, otherwise I can't use it.

Ehhhh, looking more closely, the code was removed from the page which displays the downloaded file and moved to just after the rows are exported. This increases the risk that the last-downloaded will be reset before the file is successfully delivered to the user. The UI download uses some javascript trickery to display the file.

This isn't going to be quite as easy as I hoped.

This was made harder because the $_SESSION super-global this is used to communicate the results of the export to the next page load does not work with the command line.

Committed to 7.x-4.x.

Up-port needed.

Committed and pushed to 8.x-4.x.