I didn't realize it was a fork, since it was hosted on the official repo; I thought it was just a Qt-ish interface to the official engine.
Well, it indeed was hosted in official repo, and was counted as "port", not a "fork". But there are a few things to consider:Qt port does a lot of things differently from other WebKit ports, e.g. it uses Qt for networking, graphics, has lots of other custom code paths Stable versions (both those released as a part of Qt and standalone) are technically forks, since they are based on branch starting in upstream WebKit and containing modifications on top of that Right now few people in WebKit community around webkit.org are aware of Qt port and its peculiarities; I'm probably the only one
Also, question in this topic is of a kind "go profile & debug it on device" - so, instead of asking on forums, author should either sit down and do it (and return with more concrete results/questions if problem persists), or hire someone to do that (on that specific device or similar one).