Update to only allow clamping after a line

Author: andreubotella

css-overflow-4/Overview.bs

@@ -712,8 +712,8 @@ Indicating Block-Axis Overflow: the 'block-ellipsis' property
 	It only affects line boxes contained directly by the block container itself,
 	but as it inherits, will have an effect on descendants’ line boxes unless overridden.
 
-	This property only affects a line box if there is eiher a [=region break=] or a [=clamp point=]
-	after it in the [=block formatting context=], and there are no boxes or line boxes in between.
+	This property only affects a line box if it immediately precedes
+	eiher a [=region break=] or a [=clamp point=] in the [=block formatting context=].
 	If the [=clamp point=] is placed at the end of the [=line-clamp container=], then the line will
 	not be affected.
 
@@ -1169,26 +1169,18 @@ Fragmentation of Overflow: the 'continue' property
 	additionally follows the rules in this section. All line-clamp containers contain a
 	clamp point, which is one of the following positions inside it:
 
-	- The start of the line-clamp container.
-	- A point between two [=in-flow=] sibling boxes in the line-clamp
-		container's [=block formatting context=].
-	- A point between two [=line boxes=] in an in-flow [=inline formatting
-		context=] inside the line-clamp container's [=block formatting context=].
-	- The end of the line-clamp container.
-
-	Note: The [=clamp point=] can never be before a parent box's first child, or
-	after a parent box's last child, unless that parent box is the line-clamp
-	container. Similarly, the clamp point can never be before the first line or
-	after the first line of an [=inline formatting context=]. It can also never
-	be in [=out-of-flow=] content, or inside an [=independent formatting
-	context=].
+	- A point immediately after a [=line box=] in the line-clamp container's [=block formatting
+	  context=].
+	- The end of the line-clamp container, if there are any boxes after the last [=inline formatting
+	  context=] in the line-clamp container's [=block formatting context=].
 
 	If the [=line-clamp container=]'s [=block formatting context root=] has a [=computed value=] of
 	'max-lines' other than ''max-lines/none'', then that property will determine the [=clamp point=].
 	Otherwise, the clamp point will be set to the last possible clamp point such that, for it and
 	all previous possible clamp points, the line-clamp container's [=automatic block size=] (as
 	determined below) is not greater than the [=block size=] the box would have if its automatic
-	block size were infinite.
+	block size were infinite; or if that is not the case for any clamp points, to the first clamp
+	point in the block formatting context.
 
 	Any boxes in a [=line-clamp container=] that follow its [=clamp point=] in the box tree, as well
 	as any [=line boxes=] that follow it inside an [=inline formatting context=], will be invisible