Re: temporarily overriding paper variables

[Werner LEMBERG]

> %%%%
> \markup \with-dimensions #'(0 . 0) #'(2.5 . 0)
>   \general-align #Y #UP "foo"
> %%%%
> 
> The vertical extents #'(0 . -2.5) and #'(2.5 . 0) both have the same
> effective height of -2.5 units, however they have a different
> relative starting point which is important for what may appear
> *below* the markup.

Aah, thanks.

> Also, do use \general-align to avoid futzing with \vspace in your
> markup.

Excellent advice, thanks again.

Alas, it *still* doesn't work as expected.  Obviously, I have
simplified the code example too much: adding a `ChordNames` context
prevents alignment.  Note that the top skyline of the chord symbol
doesn't show anything suspicious.

```
\paper {
  left-margin = 0
  right-margin = 0
  top-margin = 0
  bottom-margin = 0

  oddHeaderMarkup = ##f
  evenHeaderMarkup = ##f
  oddFooterMarkup = ##f
  evenFooterMarkup = ##f

  top-markup-spacing.basic-distance = 0
  top-markup-spacing.minimum-distance = 0
  top-markup-spacing.padding = 0
  top-markup-spacing.stretchability = 0

  top-system-spacing.basic-distance = 0
  top-system-spacing.minimum-distance = 0
  top-system-spacing.padding = 0
  top-system-spacing.stretchability = 0

  markup-system-spacing.basic-distance = 0
  markup-system-spacing.minimum-distance = 0
  markup-system-spacing.padding = 2.5
  markup-system-spacing.stretchability = 0

  ragged-bottom = ##t
  ragged-last-bottom = ##t

  indent = 1\cm
}

\markup \with-dimensions #'(0 . 0) #'(2.5 . 0) \column {
  \general-align #Y #UP
  "foo"
}

\score {
  <<
    \new ChordNames \chordmode { f1:7 }
    \new Staff { f'4 }
  >>
}
```


    Werner