QNTM-5426: Adding null checks to harden return from CreateNodeFromShortName

[ColinDayOrg]

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Purpose

While addressing a crash it was determined that there was a path that a null value could be returned when there was no null check, which could lead to other possible crashes. This PR is intended to guard against possible null returns leading to a crash. Note that it is not intended to make the code fully functional in the event of exceptional circumstances, just to guard against crashing.

This PR currently only addresses the first three levels after the initial CreateNodeFromShortName possible method null return. There is still another level (or more) of null checks needed to definitively handle the null possibilities, but it seemed that the changes were leading to diminishing returns. This work can be continued using the notes in the associated JIRA issue (QNTM-5426).

Declarations

Check these if you believe they are true

• The code base is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning, and are documented in the API Changes document.

Reviewers

@aparajit-pratap

FYIs

@mjkkirschner

[aparajit-pratap]

How about checking for if string.IsNullOrEmpty(name)?

[ColinDayOrg]

I have updated the code to use IsNullOrEmpty instead.

[aparajit-pratap]

Thanks @ColinDayOrg LGTM.