Map options from settings are merged incorrectly

[JoshKarpel]

In #198 , @keith6014 noted that

I also did this

htmap.settings['MAP_OPTIONS.executable']=sys.executable

The job still gets held. Same held reason. But I get a different stderr.

can't open file '0': [Error 2] No such file or directory

which is actually a bug all on its own; it wasn't intentional that map options from settings can bypass the reserved descriptors check (executable is reserved), but that is indeed exactly what happens, because that check only occurs when constructing the MapOptions, but the settings map options are merged in during create_submit_object_and_itemdata() via get_base_descriptors(). See

htmap/htmap/options.py

Line 287 in bb20219

**from_settings,

Not quite sure what the logic was supposed to be here, but it's wrong. The intent is that map options in settings should be injected into all MapOptions, so we should probably just do that in the constructor. Might be worth another look at how MapOptions are built up in the first place, because they're pretty weird under the hood.

[JoshKarpel]

Another case: setting MAP_OPTION.fixed_input_files bypasses

htmap/htmap/options.py

Line 103 in bb20219

if fixed_input_files is None:

.

The core problem here is that the merge is happening at the wrong location, and therefore does not serve the intended purpose. Need to think hard about what the intent of default options from settings is, which will indicate where they should be merged, especially given that they can't really be Python types.