Patch against r49908

When a continuation is needed for the "second" query, generator=backlinks returns a continue parameter with an empty "id1". It turns out there is a one-line fix, we just need to make sure to fill in pageMap in the generator case.

In the attached patch, I also updated the docs since this module using titles has not been the case since r34518, and adjusted the description for 'limit' to make it clear that you may actually get up to 2*limit results (which can be an issue when feeding prop=revisions&rvprop=content or other queries using the slow-query limit).

Version: 1.15.x
Severity: normal
URL: http://en.wikipedia.org/w/api.php?format=jsonfm&action=query&generator=backlinks&gblnamespace=2&gbltitle=User:Anomie/Backlink_test&gbllimit=2&gblredirect=1

Attached: