Calculate mid more safely

Philippus · Philippus · commit 0cba2f91bbf3 · 2019-04-10T21:55:44.000+02:00
diff --git a/shared/src/main/scala/scala/util/parsing/input/OffsetPosition.scala b/shared/src/main/scala/scala/util/parsing/input/OffsetPosition.scala
@@ -53,7 +53,7 @@ case class OffsetPosition(source: CharSequence, offset: Int) extends Position {
     var lo = 0
     var hi = index.length - 1
     while (lo + 1 < hi) {
-      val mid = (hi + lo) / 2
+      val mid = lo + ((hi - lo) / 2)
       if (offset < index(mid)) hi = mid
       else lo = mid
     }

Original file line number	Diff line number	Diff line change
`@@ -53,7 +53,7 @@ case class OffsetPosition(source: CharSequence, offset: Int) extends Position {`
`53`	`53`	`var lo = 0`
`54`	`54`	`var hi = index.length - 1`
`55`	`55`	`while (lo + 1 < hi) {`
`56`		`- val mid = (hi + lo) / 2`
	`56`	`+ val mid = lo + ((hi - lo) / 2)`
`57`	`57`	`if (offset < index(mid)) hi = mid`
`58`	`58`	`else lo = mid`
`59`	`59`	`}`