[Groff] gropdf ellipsis (u+2026) breaks with several fonts

[Ellam ByDefault]

I'm writing a document parser which outputs to groff to be processed with
gropdf.
When the parse document contains unicode ellipsis (u+2026), it goes fine
with few groff fonts, namely Times, Helvetica, Courier.
But with Palatino and the rest, the document breaks when processed with
gropdf, emits this message:

Use of uninitialized value $fld in concatenation (.) or string at
usr/local/bin/gropdf line 1923, <> line 6838.

While with grops everything is OK.

What happens?

Cheers from Indonesia,
Ellam ByDefault