Subsequent JQL clauses deleted in Advanced Search when choosing an auto-complete suggestion

Summary

When modifying an Advanced Search JQL and choosing an autocomplete suggestion (e.g., a custom field), if you do not enter both ""(quotes) before selecting the item from the auto-complete suggestions all subsequent clauses are removed from the query.

Adding the closing quote does prevent the deletion of all subsequent clauses, but it also leads to a partial overwrite of the existing clauses (the same number of characters as the drop-down suggestion, in fact).

Environment

Reproducible in 7.3+.

Steps to Reproduce

1. Perform an Advanced Search with JQL (Example: project = test and issuetype = Task)
2. Modify the search to add a custom field parameter prior to the last clause (Example: project = test and "My Field" = Foo and issuetype = Task)
3. When attempting this, notice that the issuetype clause is removed from the query

Expected Results

It is expected that selecting the item from the auto-complete suggestion list will add it to the query without impacting subsequent clauses.  

Actual Results

The actual results are that all subsequent clauses are lost from the query. 

Notes

It looks like this functionality was added in JIRA Agile 6.1.3  The problem is not reproducible from this version through, at least, 7.2.7.  

Workaround

Adding both an opening and closing quote before entering the item name and selecting from the auto-complete suggestion list will persist the subsequent clauses.