Trailing whitespace that could produce a hard break but won't due to context should also be flagged by MD009

[TheJaredWilcurt]

* Example
  * The next line has 2 spaces
  
  * The line above this should be flagged for trailing whitespace

There are two spaces on the 3rd line that should be flagged as trailing whitespace.
Here are the rules I'm using, in case I have something set wrong:

• https://github.com/TheJaredWilcurt/tjw-markdownlint-rules/blob/master/tjwmarkdownlint.yml

Here it is again, but with the spaces replaced by hearts to make it easier to see

*♥asdf
♥♥*♥zxcv
♥♥
♥♥*♥qwer

[DavidAnson]

Exactly 2 trailing spaces has a special meaning in Markdown. If you change your example to just one space or three+, MD009 will fire as expected. You can use the br_spaces perimeter to report issues for two spaces as well. More detail is available in the documentation here: https://github.com/DavidAnson/markdownlint/blob/master/doc/Rules.md#md009---trailing-spaces

[TheJaredWilcurt]

I understand the 2 spaces being a <br>, but that should only be at the end of a line with content.

In this context, it is obvious that it is an indentation placed by the editor and would not be interpreted to produce a <br>. It is continuing the indentation of the previous line.

* Example
  * two space indent
    * four spaces
    
    * The above line also has 4 spaces

When it's an empty line, with nothing but spaces, in the middle of a list, it should let you auto-flag that.

[DavidAnson]

Using the br_spaces parameter I reference above should report for your original example.

MD009 could also be enhanced to understand scenarios where trailing spaces do not insert a hard break and report on that in the default configuration. Is that what you are looking for?

Context: https://spec.commonmark.org/0.29/#hard-line-breaks

[TheJaredWilcurt]

Yes, that is what I want. I'd like it to flag where trailing spaces are used but do not produce a <br>.