## Summary of Changes
The `read_..._WKT()` functions have `bool` as return type, but currently
only check if the stream is bad, which is not the case if no input was
read.
This PR was triggered by the fact that CGALlab could not WTK files with
polygons, but only polylines. It now can read polygons, but does only
draw the contours and not the interior.
## Release Management
* Affected package(s): Stream_support
* License and copyright ownership: unchanged
Sebastien Loriot
39c7001a25