export select tag behavior and documentation

[Samuel Wales]

[2020-10-31 Sat 20:59]  =x

bug
===

  9.4 maint docstring

  === org-export-select-tags is a variable defined in
  ‘ox.el’.

  ...


    1) does this take into account subtree export, region
       export, and narrowed buffers?  if so, perhaps the
       docstring should change.

       my expectation is that just having :export: in a huge
       buffer should not affect exporting a tiny part of it.
       by the principle of least surprise.

       it is sorta surprising enough that something buried
       in a subtree can affect the whole export of that
       subtree.  :)

    2) org-export-with-tasks set to

       - nil will not export a task subtree regardless of
         :export: tag underneath
       - t will export regardless

       thus basically overriding the export tag feature with
       the export with tasks feature.  is that intended?  i
       can see that it could be the best choice, but could
       also see it being useful to use the export tag even
       with tasks.

       i wonder when was the last time there was a change to
       this variable or its behavior?  i suspect there might
       have been a change, at least wrt top level todo kw
       stopping export, but i don't know.