Virtual Theme load: Check for null to actually reach the code that handles this case to t…

[leptoquark1]

Virtual Theme load: Check for null to actually reach the code that handles this case to throw the appropriate exception

Description

Actually gives the chances for a meaningful Exception when a virtual theme does not a have a physical parent theme. In the previous code this exception was not reachable, since getParentTheme returned null and in the loop it was expected to be a Model/Theme object.

Fixed Issues (if relevant)

• No Issues fixed

Manual testing scenarios

1. Create a virtual theme without a physical parent

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-cicd2]

All committers have signed the CLA.