E-book viewer: Incorrect page layout when selecting 3 pages for landscape

[etc205]

1. Open the attached file, "book.fb2", in the viewer.
2. Maximize the viewer window.
3. Right-click to open the Controls and select "Preferences -> Page layout".
4. Set "Landscape:" to 3 and click on "OK". The viewer shows not 3, but 4 pages, out of which the ones in the middle are displayed fully, and the ones on the sides partially.

Calibre version: 6.25,
OS: Windows 10 Home.

[Kovid Goyal (kovid)]

That will be because somewhere in that book there is some non-reflowable
content such as a table or <pre> text that is wider than a column. This
will break layout.

[Kovid Goyal (kovid)]

Fixed in branch master. The fix will be in the next release. calibre is usually released every alternate Friday.