Fix confused cursor positioning in clipRTLLines

FIX: Fix an infinite loop that could occur when enabling `bidiIsolates` in documents with
both bidirectional text and very long lines.

See https://issues.chromium.org/issues/342778297

src/isolate.ts

@@ -99,8 +99,12 @@ function buildDeco(view: EditorView, tree: Tree, always: boolean) {
 function clipRTLLines(ranges: readonly {from: number, to: number}[], doc: Text) {
  let cur = doc.iter(), pos = 0, result: {from: number, to: number}[] = [], last = null
  for (let {from, to} of ranges) {
- if (from != pos) {
- if (pos < from) cur.next(from - pos)
+ if (last && last.to > from) {
+ from = last.to
+ if (from >= to) continue
+ }
+ if (pos + cur.value.length < from) {
+ cur.next(from - (pos + cur.value.length))
  pos = from
  }
  for (;;) {
@@ -109,7 +113,7 @@ function clipRTLLines(ranges: readonly {from: number, to: number}[], doc: Text)
  if (last && last.to > start - 10) last.to = Math.min(to, end)
  else result.push(last = {from: start, to: Math.min(to, end)})
  }
- if (pos >= to) break
+ if (end >= to) break
  pos = end
  cur.next()
  }