bug#20322: 25.0.50; indent-tabs-mode should default to nil

[Stefan Monnier]

> However, the implementation seems to do the right thing:

> https://github.com/outsideris/popularconvention/blob/master/src/parser/js-parser.coffee#L99-L100

This seems to count the number of lines which start with a SPC and those
which start with a TAB.

If your indentation rules use an indentation step of 2, you'd likely get
many more lines that start with SPC regardless of indent-tabs-mode
(just because most lines of code are less indented than 8 columns).

So, I don't think it does the right test.  I think the right test would be

  tab = /^\t/
  space = /^\s\s\s\s\s\s\s\s/


-- Stefan