Fix XML indentation in Emacs mode The return value of MATCH-STRING is a string. At least on Emacs 25, the comparisons between string and character with EQUAL could never succeed, and so the cases for matching braces were never triggered. GET-TEXT-PROPERTY may return a list rather than an atom (for example, on long lines with whitespace-mode turned on), and this broke the heuristic of looking for the tag face in previous text.

fun main () : transaction page = return <xml>
  {[case String.split "abc{" #"{" of
        None => "!"
      | Some (pre, post) => pre ^ post]}
</xml>