Decompiler's understanding (or lack) of segments

[Wall-AF]

I'm trying to understand how the decompiler (C++) code is supposed to work with segments. To this end, I've added a warningHeader message within int4 ActionSegmentize::apply(Funcdata &data) to see what's going on, and I've discovered that out of 4 userops.numSegmentOps() only 1 seems to be defined. It is the last, has the segdef->getName() of "segment" and belongs to to address space "ram" (using the x86-16.cspec).

To me, this seems wrong. I say this because in this cspec file there are actually 6 segment registers (DS, CS, ES, FS, GS & SS) and when the decompiler dereferences a segment op, it always seems to use the DS (therefore as its default). I see this (although this example shouldn't even be referencing any segment, it does) when a simple PUSH 0x1305 is being treated as an address, and by changing the value in DS to 0 enables the decompiler to realise it as a number and show its appropriate enum value. Other situations occur when a function address is placed upon the stack, and the DS value is used instead of the value in CS (or whichever segment was recently pushed).

Does anyone have insight they can share here???