bug#69908: dist-no-built-sources vs. no-dist-built-sources vs. dist-built-sources

Hi,

I have seen https://debbugs.gnu.org/49317 and the two commits 13659a7 
and especially 314c55f. I also recognized there is a test case to test 
for the correct behaviour.

Nevertheless I think there is something wrong here. I tried to make it 
work yesterday via AUTOMAKE_OPTIONS (tried both root dir and the 
affected folder) as well as via AM_INIT_AUTOMAKE, neither of them 
produced the expected Makefile. No matter which way I tried, I always 
ended up with

     distdir: $(BUILT_SOURCES)
         $(MAKE) $(AM_MAKEFLAGS) distdir-am

which, according to both the code in lib/am/distdir.am and the docs 
should not happen, if that option is set.

After looking at these commits again I noticed that although the option 
is named "no-dist-built-sources" (see lib/Automake/Options.pm and the 
docs), the code in bin/automake.in to initialize the DIST_BUILT_SOURCES 
flag tests against sth. else:

     'DIST_BUILT_SOURCES' => !! option 'dist-built-sources',

Which raised the question, whether that feature really works as 
intended, or if it could be broken since 314c55f and the test might not 
work properly for some strange reason?

What am I overlooking? What am I doing wrong?

Thanks,
JensG

PS:The headline refers to the three different variants of that option as 
found in code and commit messages.