Hi Mark - thanks for the report. it seems to me that the least bad approach is to correct the documentation and usage messages to describe it accurately, with a historical note in the manual explaining the long-standing error in previous versions of the documentation.
I agree. Would you be up for writing a draft patch? Given the research you've already done to send this report, you're certainly more familiar with the relevant places than me (by several miles :). I guess that hardly anyone writes Automake test drivers. :-/ I guess so too. (Yes, I am considering doing this.) If so ... happy driving :). --thanks again, karl.