Summary:

In some pptx files (possible due to them being created on google slides and then exported to pptx) images do not have the idx set (as they're part of a layout?)

PR - Merge Checklist:

-- Verify:

• ALL tests have passed
• Code Review is done
• Documentation updated or N/A
• Dependencies satisfied

I see this is a duplicate of #190

@pterk I'm going to leave this one open if that's okay. This shows exactly how to fix it and I like the approach; I think it's the most sensible "compensation" for the invalid XML, it definitely won't make the XML any worse :) I'm going to try to get this into the next release, should have one going in sometime in the next couple weeks.

Definitely okay ;-) Thanks again for the nice software!

This is fixed in release v0.6.6.

Retire a few shortlist issues before release.