Indentation depends on if a line is blank or not

The following program is indented with cmd-i (Except the | marks the end of a blank line not a pipe character in the file):

#lang scribble/base
@list{
      |
}
@list{
 a
}

As you can see the line after the @list{ indents to a different depth depending on if the line has content or not.

While this usually doesn't effect the rendering of anything and is mostly invisible, it winds up being annoying because I wind up with the situation <return> <types some text> "Why is this indented so oddly?!", then needing to remember I must reindent after adding text to a new line.

Reproduce the behavior in DrRacket with the provided Scribble program, using cmd-i on blank and non-blank lines. Trace the indentation entry point for Scribble code and make the indentation after @list{ consistent regardless of whether the line is blank, then verify both examples produce the same indentation.