When a function is under a namespace then this will not show up under the index for Qt Assistant

When a function is under a namespace then this will not show up under the index for Qt Assistant. It is listed in the index file correctly, but cannot be found when trying to type it in the index.

For example: convertFromPlainText (in the Qt Namespace) or blockingFilter (in the QtConcurrent Namespace) have documentation but are not listed when typing it in the index search.