1702455 - log viewer first 1m+ lines not shown

Status: NEW

(Tree Management :: Treeherder, defect)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://treeherder.mozilla.org/logviewer?job_id=334928008&repo=mozilla-central&lineNumber=4116 doesn't show the first lines of the log but starts with line 1182310.

react-lazylog limits the output height: https://github.com/mozilla-frontend-infra/react-lazylog/blob/962d294b18dd657a0c84ab05062a6bd8339c8180/src/components/LazyLog/index.jsx#L34-L36 (since its initial implementation)
But when text gets selected and scrolled out of view and scrolled back into view, the selection is gone. A similar algorithm might be used to let the user go to the start of the log.