Unexpected tuplet bracket location

[Victor Eijkhout]

Is this a bug or a feature?

quartertriplet = { \set tupletSpannerDuration = #(ly:make-moment 1 4) }
\relative { \time 3/4 \clef treble \key g \minor
\relative c'' {
\quartertriplet
\times 2/3 { r8 a r a r4} r4 | r8 g r g r4 |
\times 2/3 { r8 a r a r4} r4 | r8 bes r bes r4 |
\times 2/3 { r8 c r c r4} r4 | r8 bes r bes r4 |
\times 2/3 { r8 a r a r a} r8 a | r4. g |
}
}
\version "2.9.27"

Same output with 2.9.something and 2.10.

Victor.