[Qgis-user] Merge does work (at least not as I expect)

[qgis-user at stripfamily.net]

I have a layer with a single multi-linestring, containing ~2000
segments. I have verified (by exporting as CSV with geometry as wkt)
that the endpoint of each segment is coincident with the start point of
the next to the nine decimal places shown in the wkt. I run
Processing-->Vector Geometry-> Merge lines  and the output is a  new
layer containing a single multilinesegment equal to the original. Seems
like all segments should have been merged into a single linestring. Any
thoughts as to what's going on?
Thx