Invalid argument supplied for foreach() in twitter_pull_preprocess()

Intermittently receiving the following error:

Warning: Invalid argument supplied for foreach() in twitter_pull_preprocess() 
(line 65 of sites/all/modules/contrib/twitter_pull/twitter_pull.module).

Not sure if API issue, so could be a dupe of another issue.
Proposing to remedy by checking for existence of $variables['tweets'] first. Patch included.