Getting voices to merge in a complex measure

[Knute Snortum]

Hello everyone,

I'm engraving Chopin's Prelude No. 1 in C and I'm having trouble
getting two voices to merge.  It's the two lower d's in the last 16th
of the measure.  I've attached the source code and a picture of what
it looks like.  The second picture is how I would like it to look.  I
have notes in the source code that document some of what I discovered
fooling around with the notes.

Any help would be appreciated.

--
Knute Snortum

no-merge-voices.ly
Description: Text Data

ds-dont-merge.png
Description: PNG image

wanted.png
Description: PNG image