\caps and \smallCaps don't work with \fromproperty

[Mark Polesky]

In the example below, \caps and \smallCaps work with simple text
strings, but not with text fields accessed with \fromproperty.
For some reason, this is not a problem with \sans, \italic, and
\bold; they all work with both text strings and \fromproperty
fields.

This is not the expected behavior.  Users should be allowed to use
\caps and \smallCaps with \fromproperty in the definitions of
bookTitleMarkup et. al.

Thanks.
- Mark

\version "2.13.44"

\paper {
  line-width = 80\mm
  bookTitleMarkup = \markup {
    \column {
      \fill-line {
        \line { \sans "Sans" }
        \line { \caps "Caps" }
        \line { \smallCaps "SmallCaps" }
        \line { \italic "Italic" }
        \line { \bold "Bold" }
      }
      \fill-line {
        \line { \sans \fromproperty #'header:title }
        \line { \caps \fromproperty #'header:title }
        \line { \smallCaps \fromproperty #'header:title }
        \line { \italic \fromproperty #'header:title }
        \line { \bold \fromproperty #'header:title }
      }
    }
  }
}

\header {
  title = "Title"
  tagline = ##f
}

\markup \null

caps-fromproperty.png
Description: PNG image