puppetlabs/puppetlabs-apt — pull request #330 by dantman (2014-07-11 00:13:25+00:00)
Title: Fix inconsistent $proxy_host handling in apt and apt::ppa.

- The default for $proxy_host is undef
- apt considers $proxy_set to be absent if $proxy_host is undef
- apt::ppa considers proxy_env to be empty if $proxy_host is false or ''

This results in apt::ppa to consider $proxy_host to be set when the default undef is used
breaking ppa resources because $proxy_env becomes:
[http_proxy=http://:8080, https_proxy=http://:8080]

Fix this by making both apt and apt::ppa consider $proxy_host to be unset when it is
any of false, '', or undef.
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Please merge and release, apt::ppa is unusable as-is.