to make it easier for a downloader to fetch them.
Those seem to be showing up on Longreads, in particular.
This may solve a lot of the images that weren't downloading. Guard against images that don't download; don't bomb out with errors, and rewrite the URL to an absolute one so the image will at least show if there's a live net connection.
Include a note in the indexstr for pages with blank content.
and links that only span spaces. (E.g. Slashdot RSS.)
…h them over http
…he current site (so we don't end up with no index)
Also, it's not necessary to decrement pagenum in case of errors; it's calculated again each time from its position in suburls.